Thank you, DannisSpace! I didn't know about the other game, but I am glad that other people thought of a similar game. Let me answer your questions. You control the empty tile with the touchpad, so when you press Up, the empty tile goes up, so naturally the tile there will have to go down. I have always played this game like this, and I can't even imagine it the other way around - hahah. The reason I didn't use the touch feature of the Zune pad is that it is too sensitive, and the tiles will be flying around. Even like this, the game drives me crazy when I click a diagonal direction by mistake, and then the empty tile moves two times, up and right for example.
I am thinking of what other game to make. I want it to be something related to music or pictures, since it is going to be for the Zune. If you have any ideas, feel free to share!