Fantastic hack!! Changes the overall world map and enemy placements to an almost one-to-one copy of Super Metroid. Some creative and interesting improvisations have been made where Super Metroid's elements weren't present in Zero Mission's engine, such as Green Gates/Wave Gates and certain enemies and bosses.
Crocomire makes an appearance, Ridley & Kraid are vanilla, while other bosses have been "re-imagined" to their closest Zero Mission counterparts. As of 3.0 I think the bosses still need some balance (that is, more hp) as some bosses are too easy under the Super Metroid loadout conditions.
A variety of cool tech is still possible, such as Early PBs up Red Tower (via bomb jumping) and Early Wrecked Ship (via Ocean Fly/Moat Bomb Jump). Other tech is conversely rendered impossible in Zero Mission's engine - such as the absence of Mock ball and the Green/Wave Gate glitch.
Overall this is an incredibly interesting and very well made hack that offers yet another cool opportunity to play through the same Zebes you likely know and love, but with some differences in tech and mechanics to keep things fresh and exciting