Sonic Robo Blast 2 is a free 3D Sonic the Hedgehog fan-game built using a modified version of the Doom Legacy source 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 also providing a full host of multiplayer modes and features in a fast-paced mix of FPS and platforming gameplay.