Flat Zone is an unlockable stage in Super Smash Bros. Melee. The place is located in Superflat World, and is Mr. Game & Watch's home stage. It is unlocked by beating Classic or Adventure as Mr. Game & Watch at least once.
Flat Zone is set within a Game & Watch system of the Widescreen series, with the title Smash Bros. on the right-hand side. The stage is based on Helmet, Oil Panic, and Manhole.
Its main gimmick is a figure hanging on the platforms, who will move occasionally, causing some parts of the platform to move somewhere else. Other less common features are falling wrenches, buckets, and other tools. Although that doesn't sound too bad, the tools are incredibly devastating to lower handicapped players (being able to KO them at low damage), while being just a nuisance to higher handicapped players. Also, a man carrying oil will pass by and drop it onto the Stage, making that ground very slippery.
- No 40: All-Star Match 4 (Mr. Game & Watch's fight)
- No 45: Game & Watch Forever!
- If any players get KO'd by any falling tools, they will always get an SD (self-destruct), regardless of if they were attacked by their opponents before getting hit by the tools. This also means that players can't earn KOs by having the tools KO their opponents.
- A similar Flat Zone screen appears in Mr. Game & Watch's Target Test stage.
- Super Smash Bros. Brawl features an new Game & Watch-themed stage known as Flat Zone 2. The music from the original Flat Zone plays on the stage in My Music. Unlike Flat Zone, Flat Zone 2 is always in a fixed-camera position.