The following post will meander a bit as I wrote it in a kind of stream of consciousness state.

I don’t know where you heard that Super Metroid was originally a remake of the NES game, I’d never heard that and I can’t find anything to back that up. As well, keep in mind that Super Metroid came out a full decade before Zero Mission did, and the original NES game that Zero Mission is a remake of was even lighter on story than Super is. If you aren’t enjoying Super because of a lack of story that’s fine, you won’t miss much if you skip it, though I will warn you that a very common complaint about fusion is that until basically the very end the game is extremely linear. That said, I also think it’s unfair to call Zero Mission an asset flip, it’s much more a full on remake. Back to the Super Metroid thing, I will point out that the Wrecked Ship in Super Metroid is mostly not the Wrecked Ship you traverse in Zero Mission, there’s like one screen that is shared between the two games.