My criteria for a truly standout Metroid hack is thus:

• Jumping/moving physics fine-tuned to feel more like those of Super Metroid.
• Ability to jump while in ball form.
• Ability to shoot downward (and perhaps upward at 45 degree angles).
• Simultaneous Wave/Ice Beam.
• Addition of a new offensive weapon, like Super Missiles or the Hyperbeam.
• Remixed/new music.

Granted, these are all things I intend to include in my hack (circa 2015), but I wouldn't mind getting one-upped on a few of those. Conversely, if something on that list piques your interest, but is outside your realm of expertise (soundtrack hacking tends to require both a working knowledge of 6502 *and* music theory), I could offer my services as a collaborator. Some preliminary familiarization with the Metroid ROM would be a valuable asset come 2013-ish.

Ah, your official green belt project! Congrats.  :cookie:

Aside from the level/layout and possible graphics updates, is there anything else you're planning on doing in this hack?

Absolutely!

I'd start by locating the RAM location of the "Samus Form" byte. This could take several forms, the simplest being a simple 00/01 dichotomy. (It could be more complex though, as in a byte which reflects multiple status types, i.e. standing, pointing upward, jumping, plummeting downward, etc.)

If you find a single RAM byte that reflects something resembling the former scenario (i.e. $00 if Samus is a ball, and $01 if she isn't), set a read-breakpoint at that location. There might be several reads-per-second of that byte, so you could wind up in "winter wonderland", i.e. a perpetual freeze where the debugger snaps so often that you can't manipulate Samus into the situation you actually want to test (which in this case would be hitting the A button while in ball form).

Ultimately, what we're looking for is a subroutine that checks to see if the A button is being pressed (indicating the player's intention to jump), THEN checks to see if Samus is in ball form. This will be the routine which tells the game to bring Samus out of ball form; we want to change this into a "jump as ball" command. You'll have to analyze the current Jump Handler to determine how the game handles regular jumping, then write a similar routine geared towards keeping Samus in ball form while performing these jumps.