They needn't be specific in nature, but maybe just in appearance. Consider this: if you were to play as a Henchman and as Rayman and as Globox, they would all have something in common: they can all attack. However, the way in which they attack may vary. Henchmen would shoot lazor, Rayman could either shoot majik or pound with his fists (which is up to the developers) and Globox would almost certainly be forced to slap stuff (unless he starts shooting energy out of his mouth that's been trapped there ever since he ate a bunch of Yellow Lums). In essence, all attacks do the same thing, but they could give the player more satisfaction when using them, because they would know that their attack is unique to them.