its not possible
Dead.
I've beat the game as a T-Rex and the last boss was an ankylosaurus. Be prepared for this boss cause the battle is frustrating.
at a gate with a crack
I dont have the game but I think you have to battle the Boss pokemon.
Be a boss
No, you have to beat the boss on level 5 as tiny Mario to unlock level 7.
beat boss battle with 20 people in brawl
The boss of level 2, the Moon dungeon, is a Dodongo, and to beat it, simply drop a bomb in front of it so it can swallow it. You have to do this twice in order to beat it.
Be a boss
To unlock Boss Battle Mode which is located in Stadium in Solo Mode you have to beat the Subspace Emissary.
you beat friezas boss battle
Kill the boss in the last level.