Yeah. They are essentially minigames, and no one cares about those.

What you have to do is that you have to fight 12 of them, and complete their tasks (ranging from "strike 120 times in 5 seconds," or "shoot down 100 in a minute"). Afterwards, the thirteenth will give you the MOXIII Keyblade. It's not as good as Ultima Weapon, but still a part of Jiminy's Journal.

This link leads directly to Utawarezen's third page, where the clips are. However, this is subject to change, as he also updates .hack videos for his viewers.