Other mistake: Shadow of the Colossal Donut - Homer and Bart's main and only objective in this level is to open each of the three hatches inside Lard Lad and rip out the circuits inside him. To open the hatch, Bart will need to launch a slingshot at Lard Lad's hatches. After the hatch is opened, and you rip the circuits out, the hatch will always vanish completely.
Add timeCasual Person
Picture added by Casual Person