Goombas first appeared in the original Super Mario Bros., programmed as the most common and most basic enemy in the series. They simply walk around, turning around at walls and falling from ledges, and hurt Mario on contact, but they can be quickly dispatched by jumping on them. In some later games like Super Mario 64 they actively pursuit a nearby player, but still remain very weak. Bigger versions also exist, which also commonly split into smaller Goombas when attacked.
As an enemy
Goombas are common enemies that appear in the Mushroom Kingdom stage of Adventure Mode. They can also have a chance of coming out of Crates, Barrels, Capsules, and Party Balls in VS Mode. Goombas walk back and forth on the arena, and thus often walk off the edge of a stage. Nearly every attack can KO a Goomba in one hit, and jumping on them or throwing them will KO them instantly; if the player makes contact with one in any other way, they will take damage with moderately low knockback. For every Goomba the player KOs, they get 150 points as the Goomba KO bonus.
In VS Mode, Goombas inflict 8% damage on a player who makes contact with them. In Adventure Mode, the amount of damage it inflicts depends on the difficulty setting.
As a background element
Goombas also appear in the background of the Mushroom Kingdom stage, using their original sprite from Super Mario Bros. on the NES.
Goomba is a special stage that can only be played in Event 14: Trophy Tussle 1. The battle takes place on top of an enlarged Goomba trophy, which can be won upon completing the event. The edges of the head can be grabbed if a character tries to recover.
The Goomba trophy is unlocked by completing Event 14: Trophy Tussle 1 for the first time.
Goombas make an appearance in The Subspace Emissary as enemies. They simply walk around, and upon noticing a player they start charging them: unlike their Melee counterparts they can hurt players only during their ramming attack. Characters also now Footstool Jump when landing on one instead of bouncing up with no change in animation, which makes it harder to jump on several in a row because repeated footstools decrease in height.
Goombas are among the least threatening enemies in The Subspace Emissary. They have among the lowest HP, where most attacks will KO them in one hit even on Intense difficulty, and a jump on their head will always instantly defeat them. Their movement speed is slow (though they are slightly faster when they charge), with no ability to jump, and they appear oblivious to the player until approached. Their sole attack is slow in start-up lag and easy to guard against. Along with being slow, the Goomba's charge attack is weak, dealing low damage and knockback, having low KO potential overall even on Intense. When a Goomba begins its charge attack however, it will continue for quite a while, and if it goes past the player, it will turn around to then charge again.
HP and damage taken
It is currently unconfirmed whether Goombas have higher HP on later stages.
Goombas appear as enemies, exactly retaining their Brawl behavior and weakness.
Goombas also appear as part of the Mario-themed Vs. Enemy Team final battle.