The below description is taken from LEGO.com.
Iron Man Hulk Buster
Hulk has been trapped by the powers of Scarlet Witch and she is ready to fire an electrical bolt if he tries to escape! Place Iron Man in the cockpit of the humungous Hulk Buster suit and rush to the rescue. On the way you must fend off aerial attacks from the flying Ultron Prime. Adjust the Hulk Busterís arms and legs to create fearsome battle poses and grab the villain with the powerful hands.