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Richard Davey created this fantastic game. The gameplay is very smooth, and the graphics is very appealing. The game rule is rather simple: get all the starfishes without hitting other fishes.
The bubbles in the background is created with Stardust Particle Engine. The bubble's motion is controlled by a Gravity action and a RandomDrift action. When the bubbles hit the stage boundary, they're killed by the DeathZone action with a RectZone as the death zone. Richard also added a little details to the bubbles in the menu scene: the bubbles bounce off the fish upon collision. This is probably achieved by using a CircleDeflector that follows the position of the fish.
Cute as the fishes may seem, the game is actually kind of hard to play as it gets to later levels, or it's just because I suck at playing games :p