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Sonic Robo Blast 2 is a 3D open-source Sonic the Hedgehog fangame built using a modified version of the Doom Legacy port of Doom. SRB2 is closely inspired by the original Sonic games from the Sega Genesis, and attempts to recreate the design in 3D. While SRB2 isn't fully completed, it already features tons of levels, enemies, speed, and quite a lot of the fun that the original Sonic games provided.

Download and experience Sonic Robo Blast 2 today!

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News Updates
Releases :: Development :: Website :: Other :: Archive

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SRB2 Version 2.2 Release Trailer!

Rob Tisdell - December 5, 2019


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SRB2 version 2.2 release date set

Rob Tisdell - November 29, 2019

Hey all! It’s been a long time coming, but we’re excited to finally be releasing 2.2! We’re going to be making it available on Saturday, December 7th for all to download!

Due to the high server traffic we are expecting, 2.2 will initially only be downloadable as a torrent. If you do not have a torrent client, we are recommending Deluge, which you can find at . We will try to have a few other mirrors up, but you should be prepared for this release assuming we don’t have any. We can’t wait for you all to play! One more week!

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SRB2 2.1.25 release

Rob Tisdell - August 17, 2019

Hey all!

Sorry, this isn’t 2.2. We found a couple major issues that prevented certain mods from working, as well as patched over a few netcode exploits. We deemed these important enough to make a new patch for 2.1, because a fantastic mod was made that’s dependent on these. After you download the patch, you should head on over to the KIMOKAWAIII release thread and download that. It’s a massive mod made from various members of the community and has tons of new content for you to play through. It’s well worth your while.

As an update, we are working hard on getting 2.2 together and are building internal betas. We are not quite at the RC stage yet, but we’re getting there, and a whole bunch of stuff we didn’t think we’d actually polish has been getting some serious attention while we wait on the last few major components for the game. For anyone who hasn’t seen it yet, let me share this with you:

Also, because we always do this, changelog:

* Fixed APNG movies in OpenGL recording the game as completely black.
* Fixed FOF with slopes glitching very briefly at level load.
* Fixed PK3 folders being accidentally loaded as textures, which caused crashes sometimes.
* Fixed the game reading data from past the expected end of per-level colormaps, which could cause crashes somtimes. This happened if you made the colormap with some external program that decided to append some text to the end of the lump to tell you how it was made.
* In netgames, only the server or admins are allowed to skip credits now.
* Fixed several PolyObject physics issues:
** If you were standing on a PolyObject following waypoints, walking off its edge teleported you to the ground.
** Sometimes you could collide with thin air below or above some PolyObjects.
** PolyObjects spawned with the Crush Spawn point weren’t able to crush you properly sometimes.
* Fixed an exploit where players could steal the final hash of a login.
* Fixed ERZ3 and Pipe Towers Zone spitting console errors on being loaded.

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Version 2.1.24 release

Rob Tisdell - June 9, 2019

Hey all, 2.1.24 has been released! Find it on our downloads page! Unfortunately at this moment, there is no Mac installer, sorry. I will update this post when that has been resolved.

Update: The Mac installer is now available on the Downloads page.

I also want to take this opportunity to let you all know that this is most likely the last patch for the 2.1 version of the game, barring some major game-breaking bug we overlooked. We have been making very good progress on 2.2’s development front, and I can now, with a very high degree of confidence, confirm that version 2.2 will extremely probably be done before the end of the year (Well before then, most likely!). I would like to thank you all for your patience in waiting on this, we know that the time between 2.1’s first release and now has been quite long, but we genuinely believe that the wait will be worth it. By far is 2.2 the most drastic set of changes we’ve ever made to the game, and we’re all very excited for when we can finally share what we’ve been making with all of you. Sit tight just a little bit longer, we’re almost there!

Oh, I guess I shouldn’t forget changelog:

  • APNG recording should now work in the Linux/Mac versions.
  • Added the “banip” command, for banning people by IP.
  • Editing enchancements for music: song length, positioning, and fading features with Linedef Exec and Lua support (aka Digiku’s”MusicPlus”: see for full documentation)
  • Fixed dedicated servers timing out after the credits.
  • OpenGL: Sprite billboarding can be enabled with the “gr_spritebillboarding” console variable. This just means they’ll always face the camera rather than looking flat as paper.
  • “localhost” now works as a valid IP address to join again, after being broken since version 2.0. This means people can now join their own servers without needing to find out their local IP anymore.
  • Flash palettes can now appear in screenshots.
  • Fixed crashes in netgames that can occur in levels from PK3 files.
  • Fixed some elusive software renderer glitches that sometimes effected lighting on FOFs
  • An error message is now displayed if you mistakenly added a PNG graphic for a sprite or texture when you shouldn’t have.
  • The game should no longer be marked as modified if you added replacements for many HUD graphics, the game’s console font, or some of the graphics used in the menus.
  • Oh, yeah, and we doubled all the freeslots for editing resources, which was the whole point of this patch. =P

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SRB2 version 2.1.23a release

mazmazz - April 1, 2019

No foolin, we’ve got a new update sure to improve your robo blasting experience!

Major impact changes:

  • Fixed savegame issues by changing target platform to Sega Genesis/Megadrive. Run it with an emulator and enjoy saving at any time using savestates!
  • Reduced filesize.

This is just a small quality of life update, so no big list of changes. Have at it, and let us know what you think!

EDIT: Happy April Fools! Massive kudos to VAdaPEGA for programming the Megadrive ROM. What an achievement — it even works on real hardware via flash cart. Try it out!

Special shoutouts to Mr. Potatobadger for ripping SRB1 sprites and DragonWolfLeo for the music and additional help.

You may download the ROM in the Other Downloads section.

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SRB2 version 2.1.23 patch release

mazmazz - December 26, 2018

Here’s one more patch update to close out the year! Did we ever move this fast in SRB2’s history?

Major impact changes:

  • Campaign savegames are fixed: The two of you who play SRB2 have pointed out that Single Player savegames do not actually save your progress, even if you selected a save slot. We fixed this so that you can now get out of your chair and grab a cup of milk before you finish the game.

No big changelog this time. Have a Happy New Year!

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SRB2 version 2.1.22 patch release

mazmazz - December 25, 2018

Merry Christmas, everyone, and we hope you enjoy this very special gift! It’s not 2.2, but we’d say 2.1.22 sounds just as swell!

Major impact changes:

  • Chat Windows: For multiplayer, we added the ability to display the chat in a small window by default. Fans of SRB2 Kart will feel right at home here — now you can enjoy increased readability, spam filtering, and easy-to-use private messages between players!
  • Addons Menu: We also got the beloved Addons Menu! With all of your favorite features from Kart, you may now easily find your addon files in-game without alt-tabbing and fumbling through Windows Explorer.
  • Gamepad improvements: We have now added default gamepad buttons, so if you have a supported controller, you no longer need to dive into the options — just pick up and play! If you are upgrading, the game will add those buttons to your controls as long as a slot is open for that action.
  • 64-bit OpenGL fixes: A lot of you made it very clear to us that Eggman blew up a hole in GFZ2, so we made him pay dearly for it! All of the holes in OpenGL are now fixed for 64-bit. Additionally, we fixed a visual glitch with shields that you may have experienced in both 32-bit and 64-bit.
  • SDL stability and sound fixes: Some people experienced glitchy sound effects due to our attempt to update SDL, the program library that runs our game. A few of you may have also experienced startup and stability crashes. We have now fixed the glitchy sounds, so we are now able to package the latest SDL libraries. By extension, some of the crashes should now be resolved.

Minor impact changes:

  • PK3 sprite name fix: We realized that PK3 addons cannot name lumps with a backslash character, which prevented player skins and a few other objects from working properly. We fixed this by allowing you to use the plus character instead, so player skins can now be packaged as PK3.

    To learn how to create PK3 addons, visit our PK3 wiki page.

  • Camera tweaks: When you upgrade, you may notice that the camera view looks slightly different — perhaps less claustrophobic. Also, if you specify custom camera values in the console, they will now be saved to your config.
  • Cross-platform fixes: The macOS version was unable to write savegames for mods, so we patched that up and also fixed the path that script files are executed from. We also fixed a few music formats that did not play for that version. The Linux install packages now have srb2 added to the PATH, so you can run the game just by typing in srb2 in the Terminal.

Go after the jump to read the full list of changes!


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SRB2 version 2.1.21 patch release

mazmazz - December 7, 2018

It’s 2.1-ception! When will it end?!?! We know you love us more than Smash Bros., so have a shiny new release on our backs!

Major impact changes:

  • New default controls: We revised our default controls so that our new players may play more effectively. They default to first-person style movement controls using the W-A-S-D keys, while the camera is controlled using the mouse or arrow keys. Read How to Play for a short explanation of these controls.

    If you are upgrading from an existing SRB2 installation, you will keep your old controls.

  • Improved Gamepad Support: It is now entirely possible to operate SRB2 on a gamepad alone. Analog sticks are now active on the menu. We improved their sensitivity to be less slippery in-game. We also allow you to map any button to pop up the system menu, take a screenshot, or make a GIF. Just don’t forget to set your button controls in the Options.
  • PK3 addons: SRB2 now supports PK3-format addons! PK3 is a compressed format that allows addon authors to use a folder structure that organizes graphics, Lua, SOCs, maps, and everything else into one package. Now addons can be smaller, more organized, and more future-proof for later requirements.
  • First 64-bit release: We are now releasing SRB2 in both 32-bit and 64-bit formats. For the most demanding content, you may enjoy up to a 64% performance boost! Netgaming is compatible between 32-bit and 64-bit players. Most, if not all addons will work with the two versions.

    If you have a computer built after 2004, you can most likely run the 64-bit release.

  • Linux and macOS releases: Cross-platform is back in style! We have an APT repository link for Ubuntu and Debian users, while macOS users can download a DMG install package. Again, these versions are netgame-compatible and 99% of addons should work as intended.

    However, these are experimental releases and we may not provide them in the future. Please give us feedback and submit bugs!

Minor impact changes:

  • OpenGL performance: OpenGL has been made more performant and has received a few visual fixes. Large maps (such as Aerial Garden) now render more reliably. Screenshots and wipes now work correctly on non-native resolutions.
  • Lua additions: Lua now has support for slopes, including P_GetZAt() to get the Z position of a sloped point. You can use searchBlockmap to look for objects within proximity. For HUD, hud.enabled() and v.getLocalTransFlag() are added. There is now a PlayerQuit hook, as well as a variable to check for Ultimate Mode.
  • No more SRB2DD: As of this release, we are dumping the old srb2dd.exe. We have kept it for compatibility reasons in the past, but we did not support it. A significant bug has now prevented us from releasing it further. Please use srb2win.exe from now on — it is more stable and it has the newest fixes.

This release has a large collection of individual bug fixes, so go after the jump to read them!


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SRB2Kart has been released

Rob Tisdell - November 16, 2018

Hey all, some exciting news!

Over the past couple years there has been a major mod in the works by a number of community members, called SRB2 Kart. It is a fantastic mod that is worth trying out.

Check out its release thread here

It is primarily a multiplayer mod, but there is a 1P mode that has time attack ghosts. The mod is just as customizable as SRB2 itself, so anyone interested in trying to make levels, characters, or anything else for it is welcome to do so. I highly encourage trying out this mod.

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Sonic Robo Blast 2’s 20th Anniversary

Mystic - March 8, 2018

This month, Sonic Robo Blast 2 celebrates its 20th anniversary. Sitting down to write this post I don’t even know what to talk about. It’s been so long and I’ve spent so much of my life playing or being involved with SRB2. To start, though, we’re celebrating with a preview trailer for 2.2, and I’m sure you want to see that way more than any nostalgic ramblings I can come up with, so let’s get right to it:

We’ll let that sink in for a bit. It’s hard to overstate how much the scope of the project has expanded over the years. When I joined Sonic Team Jr. seventeen years ago, SRB2 had already been in the works for three years, and every single clip of that trailer would have been considered impossible. It’s truly hard to overstate just how much the project has expanded from the original scope, due to advances in the code base and just a stubborn desire to prove everyone wrong.

Originally, SRB2’s intention was to have only Sonic running and jumping through small stages. Maybe we’d even get him rolling! The stages were so small that it’s really hard to describe. The first version of GFZ1 had the end sign where the first Star Post currently is. GFZ2 was from there to the tunnel entrance. Yes, really. This is why very early in the project there were suggested final releases in 2000 or 2001. The game’s scope and size has become absolutely enormous compared to the early days, through a long series of advances that have utterly changed what the game is capable of. While I originally thought of going through a history of the game itself, you can find out more than I could ever cover here on the versions page of the wiki. Instead, I’m going to talk about just a few of the expansions of scope and features that have changed SRB2 from that original intention to what we have today.

One of the first significant scope increases was added as the game’s basic coding was still being made. Originally, SRB2 was planned to include only Sonic. SRB1 included only Sonic with the exception of a couple of stages where you played as Knuckles, and their gameplay was identical. XMas 0.93 introduced Tails, and also introduced his ability to fly. Tails was introduced with mostly garbage sprites, and Knuckles was introduced later with even more nonsensical sprites until the affectionately known “Ugly Knux” model-based sprites were made. The sheer introduction of multiple characters was a huge change that still continues to add variety (and work to do) to this day. Even ignoring the popularity of custom characters, SRB2 would be a very different game if it featured only Sonic.

While early versions of the game supported multiplayer, it wasn’t truly featured heavily until Demos 2 and 3. Introducing match, tag, and race mode, these versions kickstarted a much larger community than the game had previously. Back then you had to use the command line or a launcher to even play multiplayer, but a lot of people still gave it a shot thanks to the introduction of IRC chat rooms and other methods of finding people to play with. The specifics of all three modes were also incredibly different. Match and tag modes had no weapons, only basic red rings, and tag had a “No Tag” zone in the stage where you could be immune to being tagged, like a safe spot in real life tag. Race mode wasn’t a straight race, either, it was what we currently call competitive mode, the 2P mode from Sonic 2. Multiplayer has expanded in scope a lot on its own since, but even just coop requires a lot of mapping support to make sure players don’t get stuck. While in the final demo cycle we ended up spending way too much time on minor multiplayer features, there’s definitely something to be said for helping your friend through a particularly hard section.

Modding was a thing from the very start, but one thing SRB2 didn’t handle originally was map settings. In order to make a custom MAP01 not display “Greenflower Zone Act 1” at startup, you had to make a custom graphic with the name of your map in the font. Skies and music similarly had to be overwritten. Final Demo finally introduced level headers, fixing this problem. The format would be horrifying to modern level designers, though. Instead of using variables, the header had a fixed line structure with 8 lines. In order: zone name, act number, force skin, music number, next level, gametype (as a number, of course), weather, sky number. This was then inserted as a text lump named “MAPxxN”, where xx was the map. That was it. There was no way to change the fields, and yes you had to type 255 to disable force skin every time. Even with these limitations, the introduction of level headers dramatically increased the amount of custom levels being made, as it made some previously very tedious stuff quite easy. It also finally made custom level packs practical to create.

Another dramatic engine improvement in the final demo cycle we barely talk about is the blockmap generator. One of the first map size limitations a level designer will come across in Doom’s map format is the blockmap, which is created by the nodesbuilder and has a limit of 128K. To give you an idea how strongly this limits map size, THZ1 in 2.1 is just shy of 90K. Instead of requiring the blockmap to be generated by the nodesbuilder, SRB2 could now build one on its own at runtime, and in a new format that didn’t have the same filesize limitations. Without this feature, our stages couldn’t possibly approach the size they do now. Even RVZ1, one of the older and smaller maps in the game, breaks this limitation.

Version 2.0 brought a ton of things to the game overall, but probably the most dramatic is the introduction of proper zone gimmicks. Most maps made for 1.X were pretty basic, and a lot of stages would work just as fine if all the textures were swapped from one theme to another. 2.0 featured waterslides, moving ropes to grab onto, and gravity reversals. Each zone finally started to be fleshed out as a concept beyond just “factory level, water level”, and gameplay finally started to feel significantly different from map to map. This change is even more obvious when going back and trying out older mods, and noticing that basically all that changes between the zones is what texture hurts to land on. This has dramatically increased as we’ve continued work, with 2.1 expanding on it especially in improving THZ and CEZ’s gimmicks, and 2.2 will continue this even more, introducing more gimmicks, large and small.

Finally, even a retrospective would be incomplete without mentioning slopes, which are already changing the game in modding. The warnings of old that “introducing slopes would force us to rework the entire game” certainly came true. 2.2’s release was likely delayed by at least two years by the introduction of slopes. That doesn’t mean it won’t likely be worth it in the long run, but we apologize to all those that were looking forward to just a simple ACZ2+3 release back in 2015. The trailer above doesn’t even come close to touching how much slopes have completely changed SRB2, but if we get to a 30th anniversary I’m sure we’ll look back at all this work and laugh.

I’d like to leave you with another YouTube link, but in this case it’s not a video. It’s an audio preview of another expansion of scope: the GFZ1 theme from our updated soundtrack. Give it a listen and I hope you’ll join us for many more years to come.

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