CatWalkOnce, an awesome puzzle platformer game for PC, has taken control of my morning. The object of the game is to walk over each blue square once to complete a level.
Walking over a square will turn it into a red trap, which will kill you if you touch it. Naturally, it's your job to figure out a way to hit every square in the correct order. It gets really hard really fast when you have to start dealing with walking on the ceiling and walls, Gravity Man style.
There's a minimal amount of Japanese dialogue involved, but the important menus are in English, and you can jump with the "Z" button. If you're up for it, you can remap the arrow keys and Z to a gamepad with a program like Xpadder or Joy2Key.