[EDIT] Since this seems to be confusing a few people, here is how the gameplay on the bottom works: the hand automatically goes forward and stops everytime you find an object (usually some trash). To go past it, press and HOLD the keypress shown. When the hand stops at the next object, press and hold that keypress IN ADDITION to the previous ones. Once you finally find something valuable, and you press its key in addition to the previous ones, you'll get points and the hand will go back automatically. That's when you can release all the keys you've been pressing so far.

Have you lost something under the seat of your car? Have you ever tried reaching it while driving? You shouldn't. Unless you're playing this game. Avoid cars while doing finger-twister on the keyboard in "Reaching Under"!