I just played through Slice HD and I enjoyed it immensely. It's a prime example of using the touch-based interface of the iPad to create mechanics you otherwise couldn't. In short, the game is about carefully moving sharp instruments out of the way of one or more buttons in order to press them. The game has a stark surgical steel aesthetic which fit the mechanics very well. If a knife cuts you a sharp sound is heard, blood spatters the screen and you've failed the puzzle.

Which leads me to my only gripe with the game and unfortunately it's a rather big one. Not only do you fail the puzzle at hand (haha, see what I did there?), the game boots you back to the previous level.

Wait, what?

I found that to be an extremely annoying structural decision in an otherwise mechanically superb game. Curiously, the game suddenly stopped this frustrating behaviour for me about 3/4 through the game, for which I was very grateful. Whether this was a progression-based change or if I'd simply failed enough puzzles for the game to stop punishing me, I don't know.

The game contains around 20 puzzles (I forget the exact number) and as such is fairly quick to complete. I found it to be a great immersive experience and a really good use of $2.99.