Conversed: "Oh man, after that level, the boss music has never sounded so sweet".
Deconstructed: The boss has an inferiority complex that leads to suicidal tendencies. When you fight him, he refuses to fight back and begs you to finish him. When the player beats him (if the player beats him), it's a genuine Tear Jerker.
Reconstructed: ...But when he finds out that you're actually going to go through with it, he has a Freak Out and tries to take you out with all he's got!...only to be taken out in half a second.
Type 2 - Easy Levels, Hard Bosses
Straight: The bosses are much harder than the levels.
Zig Zagged: There are lots of bosses in the game. Some are hard, some are easy, some are all but impossible, some are too easy....
Averted: The bosses are as challenging as the levels themselves.
Enforced: "Sure, the levels look pretty, but it's the bosses that'll stick in the players mind. So make the levels easy so they can get to the super-tough bosses, where the real fun lies."
Lampshaded: "If you're such a Bad Ass, why did you hire such wimps to guard you?"
Invoked: "I can't trust my Mooks to take care of this guy. It's time to take matters into my own hands."
Defied: A very tough boss battle is fought...for a few seconds or turns. The boss then escapes so he can stay alive and see his Evil Plan come to fruition.
Conversed: "Oh crap. That's the boss music!"
Deconstructed: The boss's minions are on strike and do nothing to stop you on your way to the boss. While you're busy with him, they terrorize the countryside, and one of them becomes the next Big Bad.
Reconstructed: ...Only for the first Big Bad to beat the arising boss and take control of his gang (and former minions).