Rad 2
Rad 2 is a drawing game where you have to plan the shortest distance between two points. You'll start with a portal that is moving in a whirlpool pattern somewhere int he screen and a black ball somewhere else. Draw the line from portal to ball with the mouse. Remember, the two don't have to connect, you just have to make sure that when the ball drops it can roll to the portal. Release the ball with the A button and reset the line with the S button. This game gets trickier and trickier but there are multiple levels that gradually lead you to some really intricate boards so there's no getting bored with Rad 2.