An asteroid has hit the Earth and the impact induces a mega tsunami. T-Rex must run to the high ground in the mountains. Unfortunately, the landscape is filled with cactus. The fleeing Pterodactyls too are on the way.

As luck would have it, our T-Rex has evolved to breathe fire, but only when it's up in the air where methane is abundance. Tap when T-Rex is jumping to shoot the Pterodactyls down.