I think there's a lot going for this game in general. It's derived from a unique concept with a uniquely novel and inspired take on the theme, does a great job of capturing the gameboy's soul, while implementing all of its gameplay mechanics in a complete sense despite having significant scope.
The gameplay loop itself, however, feels a bit unrefined in its execution. I think this is because mining in general takes some time to yield sufficient fossils to build a dinosaur. The gameplay mechanics themselves are also not well explained by the game. I thought that mining a single body part was actually me mining a new creature.
The answer to this concern is to streamline the process from mining to recruiting. (You could make the mining tools affect a larger area.) This will improve player "satisfaction" from mining while also helping players get to the point of the game quicker, which is assembling their party.