absolutely retardedly addictive. graphics are nice, i like the minimal style. the flashing of the big fish is a little disconcerting, and they do get rather nightmarish to avoid when the screen gets somewhat cluttered.
if i could suggest any improvement, it would probably be a larger playing area, perhaps you could implement some kind of scroll or zoom?
definitely worth playing though. you might even say that i was... *hooked*?
(i'd prefer if you didn't say that, though.)