Zero has two palettes in the ROM that aren't used in-game at all. Presumably they are for some kind of charging effect. In the final game, his head crystal glows to indicate charging.
Unused Honganmer BehaviorEdit
This enemy can jump, but for whatever reason this never actually happens in-game. The code for it still exists in the game though, and can be easily triggered. He will jump a short distance (32 pixels?) towards X, then when X is in range, fire his mace-ball thing.
Unused Tombot GeneratorEdit
No idea where this was supposed to go, and the graphics won't load up correctly. This object is closed at first. When it opens up, it fires out two Tombots in one direction (which direction depends on the subID), then closes again. X can only damage the object when it is open. When it is destroyed, it starts smoking from the bottom for a bit, then stops.
Inaccessable Sound Effect Digits in Sound TestEdit
Looking through the code, I noticed that there were sound effects with IDs beyond A2, which is the maximum you can go to in the sound test. The sounds actually go up to B0 before the IDs loop back again. Sounds A3-AD don't appear to be anything. Sound AE is the music used for the Light Capsule scenes -- I guess it's a sound effect so that the music can keep playing in the background and resume where it was when Light stops talking. AF is the Hadouken sound effect.
Sound Effect B0 is much weirder. It's clearly not used in the game at all, I'm guessing it might be a test of the sound engine.
The test sound can be downloaded here
Launch Octopus Stage LeftoversEdit
Unused Jellyfish EnemyEdit
This enemy doesn't appear at all in the game, and its behavior is completely unique. It has the same ID as the Sine Faller enemy, but has a subID of 1. The enemy falls down from the ceiling and swoops back and forth. When it collides with the ground, it drills into it, leaving only a small part of its sprite visible above ground. It only takes 1 hit to kill. The enemy graphics are loaded at the start of the stage, and are used up to the point where you face the first Anglerge boss.
There is both data and a palette for a third kind of Anglerge boss in the game. The subID for this Anglerge is 129, while the subIDs for the two Anglerges in the final game are 128 and 130. This Anglerge only blows air at X. Since the first Anglerge sucks air in, and the second Anglerge both sucks air in and blows air out, this was probably meant to go in between the two.
Unused Boss Entrance RoomEdit
Directly above the game's boss entrance room is a duplicate version of the room. This cannot be seen in the normal game as the scrolling does not usually go upwards at this point. However, it is there, just blocked off. No clue why this was left in there instead of just edited out, but it would've been cool to "drop in" to the boss area like in Flame Stag's stage in Mega Man X2.
(Original find and images by: GoldS)
These are unused in the game. The text looks like it's leftover from a preview copy of the game given out to video game magazines, or used at a gaming expo.
I have no idea what this one is for, though. Unused in the final.
This menu actually uses four different text IDs (one for the continue / end text, one for the top and bottom border, and two for the left and right borders). It could be a debug menu (something similar appears in Super Metroid), or a menu that appeared when you got a game over. Similar menus pop up in the NES Mega Man games.
This on the other hand is obvious -- it's text for an object viewer. Similar object viewers also appear in Mega Man 6 and Mega Man 7. Unfortunately it seems to have been removed from all versions of the game. There is no code that displays this text without hacking.
Debug text on the title screen. However, it's unknown as to exactly what it's supposed to do.
(All Debug Text Source: GoldS)