Frist you need two memory cards.Then get at least 60,000 battle tokens.Then go to the unlocks menu with memory card one data being used and buy a costume but save to memory card slot two.Then go to options and select load settings then load memory card slot one.(if you don't do this it won't work)After that go back to unlocks menu and buy another costume and save on memory card slot two. You must make sure you go back to options and select load settings then memeory card slot one after each and every purchase.This also works for levels,minigames and charaters I personally discovered it today and tried it.I now have every costume excpet sweet tooth.(I don't have twisted metal black)

When you are able to use a special move with Agamo, use the triangle + circle move and he will pull out his head.

Now throw it at an opponent.

Press triangle + circle again just before it hits them and it will explode, doing nice damage

On the TSUNOPOLIS stage. Cause major damage to opponits by repetivly sending tidal waves through city. I recomend trying this from a roof top your first few times. Simply throw anything you can at the flying saucer,(shooting won't work)and seek high ground, then watch your opponits tumble and slam into buildings. Keep listing for the Saucer to return and send them slaming through the city again and again. You can jump the tidal wave if you rush towards the saucer after throwing object. Timing is essintial. Surfs Up!!!