I once saw a humorous experiment where a rubber hand was put in front of a test subject, and the subject watched the fake hand being brushed with a feather while their own hand was brushed with a similar feather in exactly the same way. People began to feel as if that rubber hand was their own, and then they were surprised when the rubber hand was slammed with a very real hammer. The subjects reacted with horror, for a moment feeling as if their own hand had been broken. Slice HD elicits the same moments of horror, except with blades instead of hammers.

The $3 iPad app is graphic, filled with cold, gray coloring and splashes of red blood when your hand is "cut," and at times it can be hard to play. Take a look at a video of the game in action to see what I mean.

Ars was offered a review code to check out the game, so I responded to the e-mail and waited impatiently for the copy to come in. Then I remembered it was three freakin' dollars and I bought it myself. The video shows the entirety of the game's concept: you manipulate knives, stabbing instruments, and razors in order to hit the red button. Sometimes the objects move in ways you don't expect, and in other levels moving one piece triggers something else. It's nerve-wracking, and if you have a fear of blood or sharp objects, this is going to turn you into a shaking wreck.

The game forces you to contort your hands to move the knives or to keep knives from moving, and in one memorable moment I had to bend down and hit the red button with my nose, as my hands were all occupied. I'm not sure what would have happened had a blade flown across the screen at that moment, but I believe I might have screamed.

This is a fun game to play, and I often found myself jerking my hand back after being virtually "cut." It hurt every now and again, but just for a split second before my brain caught up with what's going on. This is one of the best uses of the touchscreen I've seen in a long time, and while a few levels ended with me being cut when I was sure my hand was far enough away from the blade, everything works well enough to avoid frustration. For about the cost of a cup of coffee, this is a game you need to try.