If you're running Windows Vista on your machine, then you're lucky enough to get the free game of Inkball. Inkball is a great single player arcade game that requires you to get the colored ball into the matching hole.
As with most arcade games, it starts out simply enough. You have a green block, some orange blocks, and four balls. The balls alternate between green and orange depending on which block they hit. Your aim is to get them to turn green by hitting a green block, then fall into the green hole for a point.
You make the balls rebound by "drawing" a line with your mouse. You corral the balls with your drawn lines to get them into that green hole. If an orange ball gets into the green hole you fail. You have to focus on one ball at a time - turning it green by getting it to hit a green block, then easing it along with "walls of lines" towards that green hole.
Of course, arcade games are never as simple as they appear. If there are breakable blocks, you have to be the matching color before you can break them. There are non-breakable blocks to make trouble for you. There are time limits to count down and confound you.
A lot of strategy and quick fingers are involved here. You have to figure out what combination of colors and hits will get you through a maze in time - and then you have to be dexterous enough to pull it off. It's like an active game of chess.
This is definitely one of those games that appeals to some people and completely frustrates other people. My boyfriend plays this game ALL the time and adores it, the challenge of figuring out the strategy to get through a given map, the fast clicking required to do it.
I on the other hand find this game immensely frustrating. The mouse movements are not precise so if you are dragging a line in place X it might not get there before the ball does, and now the ball is orange rather than green, and you are doomed.
I would definitely give the game a try if you have Vista. It is an interesting twist on arcade games, simple enough to understand, and challenging to master fully. It might become your new favorite way to pass the time!
NOTE: I do not think you can buy this game separately. It comes free with Vista, so if you're interested in this game, it might be time to upgrade to Vista!