You start the game with 10 colour swaps only and have to earn more through big combinations. An in-game tutorial as well as instruction screens explaining everything will definitely be included in the first full version of the game. Its very confusing otherwise.
The other mode of play I'm planning is Puzzle mode. Instead of a short timer that speeds up relatively quickly you start off with one single large timer that only very slowly goes down with each move you make. This will allow for a a more thought out and relaxed game.
I don't have any other plans for this one but I'm already designing a sequel to PowFish which will have additional features. For instance, I will be looking to include achievements, opponents to beat and different sprite sets & locations. I also want to take greater advantage of iPhone hardware. When I first started making this I didn't have an iPhone or an iPod Touch to test it with so wasn't very ambitious with the visual special effects.