Second Extinction is a 3-player co-op FPS—kinda like Left 4 Dead but instead of fighting zombies you're fighting mobs of dinosaurs. Mutated dinosaurs.
These mutant dinos have taken over the planet, though nobody really knows where they even came from. The remainder of humanity has fled Earth to a space station in orbit, but they're coming back with a bunch of guns to take back the planet, look for survivors, and discover what led to this dino invasion in the first place.
Dinosaurs are naturally dangerous foes, but even more so since their mutations give them special abilities like invisibility and acid attacks. But the humans aren't slouches, either, armed with upgradable weaponry and the ability to call down supply drops and airstrikes.
Below you can check out about 10 minutes of gameplay footage from Second Extinction, as the developers blow up a few hundred dinos while chatting with IGN.