As enemies, Goombas are rather pathetic. They aren't very bright and tend to attack enemies simply by charging at them (Let's face it, what else are they going to do?). They are pretty hopeless in battle since they can be defeated with a single stomp on the head, but if there's one thing Goombas have going for them, it's perseverance. It seems that no matter how many of them get flattened by Mario, the Goombas continue marching onward for the glory of Bowser without fear or hesitation. But then again, this lack of self-preservation could simply be a result of the Goombas aforementioned stupidity.
There are many Goomba sub-types that have appeared across several Mario games.