Congrats on release! The 4.0 build is awesome and the skip text function greatly boosts up the overall step, you did an amazingly great job Justin! Though I've encountered a glitch in New Game Plus and wanna report it here...
I just beat the 1st round, with Zero entered all armor upgrade capsules, and when I'm making progress in New Game Plus save data I found something isn't right; I entered Blizzard Buffalo stage and hold shot button as X, after dismissing the radar map X is locked up and can't move with buster keeps charging. I wonder if my USB controller died, closed Snes9x emulator and opened Castlevania Lecarde Chronicles but the USB controller works fine, then I treat it as minor compatible glitch on Snes9x. But similar case happened another time, that is I entered Blizzard Buffalo stage and hold shot button all the way as Zero, when I reach Buffalo's lair Zero can't move, I released shot button but it still doesn't work, I can't help but wait until Buffalo beats Zero, after restarting at checkpoint Zero still can't move... I checked Snes9x emulator input HUD it shows the shot button is always being held when the (presumably) glitch occurs, I soft reset the game but emulator input HUD is still being hold and Zero still can't move... Close and re-open emulator, re-load save file, the glitch is never encountered again... it's strange.
Also I think Zero's defense might be a little too weak against the hand attack of Godkarmachine o Inary, even with black enhancement intact, I didn't remember how the damage was in previous versions but I think the damage here is little too much; but I always have a habit of charging all sub tanks to full after X's Golden Armor enhancement so I can live with that anyway.
I was worrying about if splash jump is still intact after reading previous posts but splash jump in this build works fine at least with X.
(Edit: Splash jump works with Zero.) No other weird minor glitch occurs besides the one reported so this build is 99% ready to be the definitive version of Zero Project mod.
I like Zero's "weapon get" picture since the 4.0 open beta, it's hella cool!