AudioSurf

AudioSurf is a game that lets you "Ride your music."

It reads the music, and then it creates a "road" for your character to ride on. There are different characters, at different levels. Examples are Mono, which has only one color but you have to avoid the grays, Pointman, which has three colors and you can move a color (if you catch it while riding) into the slot of your choosing, and more that are expanded on three difficulty levels.

The objective is to get at least three Cars (as they are called) of the same color touching eachother (so you could have three cars at the bottom of the same color, they would disappear and add to your points, or you could have three cars at the bottom of different colors, and you would have to get at least 2 more of the same colors for each one to make them disappear.)

Except, in these videos, apparently using Ninja Mono (The Elite Mono) is the hardest challenge, as it is on nearly all the videos.

Videos: