Check out MEATGRINDER, an upcoming fast-paced first-person shooter set in a constantly moving environment, created by Game Developer Vampire Squid using Unity.
Described as "Clustertruck meets Duke Nukem" by the developer, the game lets you shoot dozens of enemies while traversing through its high-octane levels on top of speeding trucks, trains, and even planes using jumps, agility, and a grappling hook. According to the creator, the game features no cutscenes or storylines, offering a 100% chaotic gameplay with wild movement mechanics and "pure action".