To access Hyper Mode, beat 11 targets in Survival Mode.
Delete all your Fighters MegaMix save data. Now beat courses A-H but not I. Then place O.K. marks on 1200 moves in training. Now go to course I and press the L button. You'll enter a screen full of question marks. The object is to find the two matching pictures. Beat it once to get a picture of Janet. Beat it again to get a picture of Janet without armor. Beat it again...
Fight 500 rounds to add a "No Damage" selection to the Options Plus menu.
At the character select screen press Left Shift + Start to bring up an Options screen. From here you can adjust the game's difficulty, fight length, and more!
Play as Niku (Meatloaf):
To play as Niku you must first turn on the Saturn 30 times with the Fighters Megamix game loaded (playing counts). This only needs to be done once. Now put the cursor on Kumachan and press X...
Play as School Girl Honey:
Beat course A. Then put the cursor on Honey and press X to be red, or Z to be blue.
Play as the Palm Tree:
To fight as a palm tree, play the game for 84 hours. Now go to Kumachan and press Z. You'll be the Palm tree from the AM2 logo.
Alternatively: Clear all courses with five different characters. Play 1000 games, then play course "I". Kumachan turns into the palm tree.
Beat courses A thru I to get all the hidden characters, more options, bookkeeping, and portraits!
Remove your Armor:
To remove your own armour in normal mode (as opposed to hyper mode) use the following move: f, b, f, b+P+K+G. This move is very tricky to work at first because the timing is delicate, but the effect is worth it.
Fire Janet's Gun:
Press back, forward, P+K. If opponent is near a wall this move will take of 50% or more energy...
Press DOWN twice on the D-Pad and press buttons A+B+C (or press button Z on default setting) to teleport.
When fighting at the B.M stage, select Panda as your character and you will notice a face on the mat, Panda's face!
Thanks to Revolution readers Lenny Markus, Hugo Eric Corro and Gomez Addams, Jr.!