Here is the full list of all 13 Feesh achievements.
Last 5 minutes in Shark Attack mode O.O
Last 3 minutes in Shark Attack mode (that would impress me honestly)
Don't eat or get eaten by a feesh for 1 minute and 30 seconds
Eat 20 sharks somehow
Evolve 10 times in one game !!!!
Like just absolutely wreck the entire ecosystem pretty much. Eat 1000 whole feesh
Eat 100 Feesh. 100 WHOLE FEESH
Get shrunk back down to starting size
Eat 70 entire sharks
Other feesh are nearing extinction and are struggling to get by. But you don't care. Cause you just ate 10,000 of them
Make children Feesh 200 times!
Eat 150 red feesh! You'll be super small by the end of it tho
Earn your Feesh PhD by playing 35 games!