When you first begin a game of LEGO Marvel Super Heroes, you are in Story mode. As you take control of Iron Man, Hulk, and later Spider-Man to defeat Abomination and Sandman, you are playing the first of 15 levels. After you complete this level, you earn a Gold Brick for your effort and unlock the ability to play the level again in Free Play mode. In Story mode, you are assigned specific characters for each level. Your main objective in this mode is to complete the level. However, you may also be able to complete a few optional tasks if your characters have the correct abilities. In addition, if you can earn enough studs to achieve True Believer, you earn an additional Gold Brick.
Once you complete a level in Story mode, and have completed the first three levels, you can then go back into the level in Free Play mode. Unlike in Story mode, Free Play mode allows you to use any of the characters you have collected so far—not just the characters assigned to that mission. This allows you to bring in characters with different abilities so you can collect all ten minikits in each mission and rescue Stan Lee who is in peril. During Free Play, your objective is to complete these tasks so you can earn a couple more Gold Bricks.