Easily the best RPG ever to take place in the Silurian Period. Also, it's a really strange little game, where you evolve through various time periods. Instead of leveling up, you open the menu (Space I think) and spend your EVO points on stats. Enough points in any of the four directions, and you evolve into a unique new creature. The gameplay is kind of grindy, though.
Link to the translation group's page for the game.
Download (Game Manual)