-A bit repitive
-The challenge mode can feel a bit pointless whentrying to beat your own scores
-Very little dual-screen use
The game is, in basic terms, changing some squares of black/white to match other squares of black/white. You draw ONE line through all the black and white squares and any that you pass over become the other colour, so black goes to white and white goes to black. The aim is to get horizontal lines of the same colour some they disappear, Tetris style.
If all the lines are made out of one colour (each) then all the lines will disappear, solving the puzzle. This is how you play the puzzle side of the game. The other part is the challenge part. This is played the same as the puzzle side, but instead that set puzzles, there is a never ending (until you lose) falling mass of bits of puzzle. First they come in groups of four lines, then (once you've passed the first stage, in one lines which come at a much faster speed.
I left this score a three for a reason. This game is as only as good as the person playing thinks it is. Poeple who will like puzzle game will most probably like this, however, people who don't like puzzles won't like this. Simple, eh? I like it, but not too much, but I'm not much of a puzzler. And anyway, as I just said, it doesn't really matter what I think because you might be completely different. So, in short:
Buy if you like puzzles.