Instructions are in the game. You are a little fish trying to grow big! Eat the other fishes and grow as large as possible. Game stores the most fish anyone has eaten.
Got inspiration from those games where you are a fish and are trying to grow big, eaten smaller fishes and avoiding larger ones. I might change it so you can only eat smaller fish and larger ones eat you, but probably not. Also, there is a point where you grow large enough to take up the whole screen and eat all the fish without moving, so anyone could just wait until they get the high score, so that's also something I might change. UPDATE I changed it so that when you grow large enough, it "zooms out" so that there is a new backdrop and you grow smaller. This only happens three times, though. Also, I changed most of the graphics to vector.
