If you are looking for downloadable games based on your favorite Nick Toons, then Arcade.Nick.com is the place to be. While most of these games are priced at about $10 you can get demos, to see if you like the game before spending the money for the full game. This is often a good idea because some of the games are really lame.
There are a Lot of Sponge Bob Games that are variations of games parents would remember from Qbert, to Zaxon. There are also mindless platform jumpers like Obstacle Odyssey.