Gnat Attack

Gnat Attack is a minigame originally found in Mario Paint, in which the player must swat different fly-like enemies using a flyswatter.

Mario Paint
In Mario Paint, the player controls a gloved hand (similar to the one seen on the title screen) holding a flyswatter using the SNES Mouse, which must swat flying insects on the screen, before the insect stings the player's hand in one way or another. There are three levels, each with 100 insects; after defeating them, the boss, Watinga, appears. Completing stages causes Mario characters to walk across the screen. When the player defeats the last boss, it takes them back to level one and adds a small icon in the top left corner of the screen; there is no final level or reward, as the game will loop endlessly, getting slightly harder each time.

WarioWare, Inc.: Mega Microgame$!
Gnat Attack was modified into both a microgame and a bonus minigame in WarioWare, Inc.: Mega Microgame$!, under the names Mario Paint: Fly Swatter and plain Fly Swatter, respectively. The microgame involved shooting the flies as they flew past a fixed target, while the minigame was more faithful to Gnat Attack's gameplay.

Super Mario Maker
Gnat Attack makes a return in Super Mario Maker. The game is triggered when three flies appear during the editing mode, either through waiting for 15 minutes while leaving the game idle, moving a block, or shaking a Muncher; the second method only works at random, and the third is the fastest in terms of effectiveness. Swatting all three flies using the touchscreen will trigger the minigame. It is split into three stages, with Watinga appearing in the third stage, like in Mario Paint; each stage is completed once all of the flies in it are swatted, like in the SNES version. Since the game now uses the stylus in place of a mouse, there is no mouse cursor and therefore no need for health; instead, each stage is given a 30-second time limit. The Builder Mario costume for Costume Mario is unlocked upon beating the third stage of this game for the first time. Upon losing any stage or winning the third, the player is given an option to restart at Level 1 or quit to the editor; the game can also be exited early by pausing and touching the can of insect repellent.

The 1.20 update for Super Mario Maker released on November 4, 2015 adds a more challenging version of Gnat Attack with a pink background. It is accessible by shaking a Muncher until Watinga spawns, then swatting Watinga several times. Completing this mode will unlock the Fighter Fly costume for Costume Mario.