"1ce Upon a F1sh Kingdome"
You are Salmon, Prince of Fish
Eat small fish to become bigger.
Be eaten by big fish to become smaller.
Moving makes you smaller.
Bigger fish deeper down.
WASD or Mouse to move.
(W: up, S: down, A: left, D: right).
Scorekeeping is weird/unexplained on purpose.
Graphics are that way on purpose.
Smaller fish try harder to escape you. Similarly, larger fish try harder to catch you (and also bite harder).