Spherez is another very addictive free online game. You have to navigate your Sphere through various twists, turns and drops to reach the end goal in each level.
This is the virtual version of Labyrinth, that old wooden box game with a metal ball, and a gimbal surface controlled by two knobs. The track is very narrow, so you can fall off at any time. Rollover the Orbit gum packs to gain bonus points, but watch out for Floor Traps, Bumpers and Zappers which can throw you off.