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 a 3D environment while also providing a full host of multiplayer modes and features in a fast-paced mix of FPS and platforming gameplay.
Online multiplayer gameplay snippet of Match mode in Noxious Factory Zone - running around indoors and shooting people with Explosion Rings. At the end, you can see someone with an Elemental Shield lay down a fire trail (shield's special ability) by spindashing across the conveyor system.
Please note the yellow "Get / Send / Gamemiss / Sysmiss" text is not part of the normal HUD - it's network statistic information that I choose to have displayed when running a server (via "netstat 1" in console). I merely forgot to turn it off before recording, so just ignore it.