The aptly titled The Simpsons: Bart's Nightmare finds the bratty, but lovable, Bart Simpson trying, for once in his life, to complete his homework on time. Unfortunately, 15 minutes into his studies, he falls asleep at his desk and enters a strange dreamland filled with crawling mailboxes, floating Lisa Fairies, giant pacifiers, and other surrealisms. Bart's objective is to locate his homework papers, which have flown out the window and scattered through six different worlds: Windy World (which is the gateway to the other worlds), Bartzilla, The Temple of Maggie, Itchy & Scratchy, Bartman, and Bart's Bloodstream.
Bart is equipped with a number of boyish weapons, including the ability to burp up soda, fire a slingshot, and spit watermelon seeds. Also, depending on the theme of the level, Bart will do less conventional things, such as breath fireballs, destroy buildings, and brandish an Indiana Jones-style whip. The action ranges from running to jumping to swimming to flying to shooting to riding a skateboard, and there are plenty of obstacles and enemies to avoid and/or confront, including mud puddles, carving knives, kisses from grandma, helicopters, tanks, blue, unstable stone floors, Smithers, and Mighty Homer Kong. Most obstacles steal Bart's "Z"s (energy) while others do more unpredictable things, such as fairy dust turning him into a frog.