Sonic Robo Blast 2 (SRB2): a 3D Sonic Fan Game

Sonic Robo Blast 2 is a free, open-source 3D platformer built on a modified Doom engine that recreates the feel of classic Sega Genesis Sonic games in full 3D. Developed by a volunteer team called Sonic Team Junior, SRB2 has been in active development since 1998 and remains one of the most impressive fan-made Sonic the Hedgehog games ever created.

What Makes SRB2 Different

Most 3D Sonic games focus on scripted speed sections and linear paths. SRB2 goes the opposite direction. Levels are wide open, packed with branching routes, hidden items, and vertical exploration. It feels closer to the original Genesis games than most official 3D Sonic titles do—just with an extra dimension.

The game runs on a heavily modified version of the Doom Legacy source port. That might sound strange, but it works. The engine handles slopes, multi-layered floors, and open environments surprisingly well. And because it’s built on open-source code, the modding community has done incredible things with it.

Playable Characters

SRB2 gives players six characters, each with distinct movement abilities that completely change how you approach every stage.

Sonic is the fastest character on the ground. His signature move is the Speed Thok—a mid-air forward burst that launches him across gaps and redirects momentum instantly. He can’t gain height outside of jumping, though, so some areas are off-limits. Collecting all seven Chaos Emeralds lets Sonic transform into Super Sonic, gaining invincibility, higher jumps, and the ability to float.

Tails is the most beginner-friendly pick. He can fly, which makes clearing gaps and reaching elevated platforms straightforward. That said, flying leaves him exposed and slow, so it’s a trade-off.

Knuckles jumps lower than everyone else, but he glides through the air and climbs walls. He can also smash through certain breakable walls just by walking into them, opening paths that other characters can’t access. His Super form sends out a shockwave when he lands from a glide.

Amy Rose is unlockable after completing Frozen Hillside Zone. She has the highest jump in the game and attacks with her Piko Piko Hammer. The hammer breaks spikes and walls, hits springs for extra distance, and even grants a teammate a Pity Shield in local play. She can’t spindash, though, which forces players to find creative alternate routes. Advanced players use a technique called the “hammer cancel” to redirect momentum on a dime.

Fang the Sniper is the second unlockable character. His Tail Bounce lets him reach high areas, clear hazards, and destroy breakable floors easily. He has a very high jump on top of that.

Metal Sonic unlocks after beating the game. He has a Hover ability that keeps him airborne as long as he maintains speed, and a Boost Mode that activates when he runs fast enough for long enough. In Boost Mode, Metal Sonic tears through enemies, spikes, breakable walls, and can even run on water. He’s built for experienced players who can keep their speed up.

Campaign Zones and Level Design

The single-player campaign takes players through multiple themed zones, each split into two platforming acts and a boss fight against Dr. Eggman. Here’s what the current lineup looks like.

Greenflower Zone opens the game with gentle meadows and simple platforming. It’s short and designed to teach the basics without overwhelming anyone. Techno Hill Zone raises the stakes with a polluted industrial valley. Expect conveyor belts, electrical floors, and pools of purple slime that behave like buoyant liquid. Deep Sea Zone drops players into partially submerged ancient ruins. Waterslides and extended underwater sections force you to find air bubbles before drowning.

Castle Eggman Zone is set in a fortress suspended in the sky, complete with flag-lined corridors and Egg Guard enemies. Arid Canyon Zone floats above a barren landscape with cracked floors and oil barrels. Red Volcano Zone brings lava, tiled floors, and grassy outdoor areas together before launching players into space via a literal rocket at the end of Act 1.

Egg Rock Zone takes place inside Eggman’s space station, and Black Core Zone is where players face Metal Sonic in a race before a direct boss fight. Beating the game also unlocks hidden challenge levels—Haunted Heights Zone, Aerial Garden Zone, and Azure Temple Zone—each one significantly harder than the main campaign.

The level design rewards exploration. Secret paths, collectible emblems (200 total), and character-specific routes give every zone serious replay value.

2-Player Split-Screen

SRB2 supports 2-player local split-screen on a single computer. Players can team up or go head-to-head in a few different modes.

Co-op is the single-player campaign with a friend. Both players share the same levels and progress together. Competition works like Sonic 2’s classic two-player mode—players race through stages and get ranked on score, time, and rings collected at the end of each round. Race strips it down to pure speed. Reach the end first. That’s it.

There’s also a Sonic and Tails team-up option in single player. Tails follows Sonic around and can pick him up to fly to higher platforms. It’s a nice callback to the Genesis days.

Special Stages and Chaos Emeralds

Finding an Emerald Token hidden in a main campaign level sends players to a Special Stage. These stages are inspired by NiGHTS and require collecting Blue Spheres within a time limit. Gather all seven Chaos Emeralds to unlock Super transformations for Sonic, Knuckles, and Metal Sonic.

Modding and Community

Because SRB2 is open-source, the modding scene is massive. Custom characters, entirely new level packs, gameplay overhauls, and even full game modifications like SRB2 Kart (a kart racer built on the same engine) have come out of the community. The development team hosts an annual Official Level Design Collab where community members submit original maps that get bundled into downloadable packs.

The game’s source code is freely available, and custom content can be loaded through external files without touching the base game. Lua scripting support means modders can change gameplay mechanics at a deep level.

Platforms and Availability

SRB2 is available on Windows, macOS, and Linux. Community-made ports also exist for Android and even a browser-based version that runs on phones and tablets. The game is completely free to download from the official website at srb2.org.

Game Controls

• W / Up Arrow — Move forward
• S / Down Arrow — Move backward
• A — Strafe left
• D — Strafe right
• Left / Right Arrow — Turn
• Z / Mouse2 — Jump
• X — Spin / Spindash
• Mouse1 / Right Ctrl — Ring Toss (multiplayer)
• C — Ring Toss Normal
• Q / E — Previous / Next Weapon
• R — Reset Camera
• T — Chat
• Tab — Scores / Rankings
• ~ (Tilde) — Console
• Gamepad supported — Configurable through the Joystick Options menu

Saves:

The game saves periodically as you complete checkpoints. You can also download your save code and import it later if you’re worried about your browser cache being cleared.

Just a online port by echo on kbhgames.com

Credits

Sonic Robo Blast 2 is developed by Sonic Team Junior, a volunteer team that has grown and evolved over more than 25 years. Below are key contributors to the project:

• Johnny “Sonikku” Wallbank — Original creator and founder of Sonic Team Junior (1998). Built the original Sonic Robo Blast and started SRB2’s development. Stepped down in 2002.
• AJ “SSNTails” Freda — Lead programmer who ported SRB2 to the Doom Legacy engine. Creator of Sonic Doom 2, which inspired the engine choice. Departed after Version 2.0 released in 2009.
• Mystic — Long-time lead developer and producer. Took over leadership following SSNTails’ departure. Originally one of the earliest community modders before joining the official team.
• Chrispy Pixels — Character animator who joined from the modding community and has contributed since 2007.
• MotorRoach — Sprite artist responsible for the full character sprite overhaul in later v2.2 patches.
• SeventhSentinel — Message board administrator and community manager.
• SteelT, james, wolfs — Master server management and development.
• Nev3r (Pedro Iceta) — Developer and contributor.
• Spazzo (Michael Antonakes) — Developer and contributor.
• chromaticpipe: emscripten
• QueenDelta — Level designer, creator of Dream Hill Zone.
• Fickle — Camera system contributor implemented in v2.2.1.
• Soundtrack contributors — Malcolm Brown, David Bulmer, Cyan Helkaraxe, Jarel Jones, Stefan Rimalia, David “Big Wave Dave” Spencer, David “InstantSonic” Spencer Jr., Shane Strife, and others.
• Community contributors — Hundreds of community members have contributed levels, mods, bug reports, and feedback throughout the project’s history.

SRB2 is licensed under the GNU General Public License Version 2. Sonic Team Junior is not affiliated with SEGA or Sonic Team.

Check out Sonic Robo Blast 2 – Official Website for more information on the game.

As always, remember to have fun!