Sonic Robo Blast 2 is a free 3D Sonic the Hedgehog fan-game built off a heavily modified version of the Doom Legacy engine. It is closely inspired by the original Sonic games from the Sega Genesis, aiming to recreate their classic gameplay in 3D while also providing a full host of multiplayer modes and features in a fast-paced mix of FPS and platforming gameplay.
The Sonic Robo Blast 2 v2.0.4 patch, which addresses certain issues with network play. This patch is REQUIRED for online network play. Simply download this and extract it to your Sonic Robo Blast 2 folder, overwriting the old srb2win.exe. The full Sonic Robo Blast 2 v2.0 download is required, if you don't have that already.