Marvel Ultimate Alliance

For this achievement, you will need to unlock four outfits for every character (except Moon Knight, he only has three since he has no sim disc). The first outfit for each character starts unlocked. The second outfit is for getting 25 kills with the character. The third outfit requires 175 kills. The fourth outfit requires a Gold on their simulation.

You will obviously need to collect all the sim discs, so make sure you followed the collectible guide during the story. Also be sure to switch what character you're using during the story each time you get to 175 kills. This will cut down on the amount of grinding you have to do later. If you only use one character the entire game, you'll have hundreds if not thousands of extra kills to do later.

Refer to "Golden Age of Comics" for tips on getting simulator Golds.