A lot of creatures called fuzzballs, are released in an old wizards castle by his young apprentice. The young man is also turned into one of the fluffy creatures himself, by accident. The old wizard gets a little upset, and orders the apprentice to get rid of the fuzzballs swarming all over his castle. If he succeeds, the wizard will turn him back to human form again.
This is a platform game, with 50 levels. To complete each level, you'll have to collect all the treasures, while at the same time avoiding, or killing, various enemies. You will face mostly other fuzzballs, but also other creatures. Each level is only a single Bubble Bobblish screen, but can take a while to complete anyway.
Touching an enemy once means instant death, and if you don't complete a level in time, you will be killed by mosquitoes entering the screen. To succeed in Fuzzball, you'll have to plan every move carefully, otherwise you'll die very quickly.