Tera Kirk reviews Zooo, and says:
"There are two major subgenres in puzzle games: things falling down (Puyo Puyo! or the seminal Tetris) and things switching places. While such simplicity should be boring (and in most other videogame genres, probably would be), in a puzzle game it's almost beautiful in a Shakespearean sonnet sort of way. With only a few basic rules, a good puzzler is both comfortable and pushy. We know how it works, yet in its familiarity it asks us to do better. Can we get a combo of three instead of just two? Can we move faster? Can we get 100,000 points and a free continue? If puzzle games are measured by their ability to make us ask more of ourselves, then Zooo for the Game Boy Advance does its job pretty well."
There's more review
here.