I tried it yesterday, and as every stupid user does: did not read the instructions, so I kept scratching the stylus over the display and wondered why nothing happens
I think mouse (i.e. touchscreen) controls would be a nice addition, but the current controls work just fine (and probably better). I lost the first game pretty quickly on the normal difficulty setting, but I haven't played chess in years and wasn't trying very hard. I won on the lower setting with some rather agressive tactics. So I guess the AI should be suitable for a wide range of players.
I like the game very much, and it feels like it was made for the Pandora (and I always wanted to have a fancy looking chess-program with a difficulty-level that leaves me a good chance to win in my pocket) ^_^