There are 2 Vs the computer modes:
- Defeat 200 enemies that randomly appear in the games (not the bosses)
- Defeat 50 enemies who are the bosses
In these 2 modes, you can use any characters from the list. I especially like the 2nd one cos' you get to use any character including the new ones like Akainu or Marco. It is somewhat better than the special challenge in UC2 in which you could only use strawhats members.
Another good enhancement is; You could use many special techniques like ice age or ice ball without draining your power guage quickly