FINALLY beat it.
Holy fuck man that ending was hilarious!
You've literally compiled some of the best the NES had to offer back then.
Quite challenging! Took me three tries in three days.
----SPOILERS BELOW *(Do not read unless you really have trouble beating the game)
Hints:
Double Dragon Stage - It helps to position yourself 'slightly' above your opponents so you can hit their heads.
Mario Ocean Stage - Swim up, Swim down...makes it easier to avoid enemies.
Zelda Stage - Don't destroy all the enemies unless you have to. They often will fill up your rage meter and your hearts if you revisit a room.
Balloon Stage - Save your RAGE against difficult obstacles.
WWF Stage - Use up all the chairs and just keep button mashing. Constantly throwing Amazon on the ground.
Megaman Stage - Don't go crazy with the gun.
Contra Stage - It's fairly easy once you've entered the 'secret' code. But the best weapon of choice against Kirby is the shot gun.
Punch Out Stage - Dodge first, then punch. Save your RAGE for the second stage.