As it can be seen on the screenshots alone, the game received a general overhaul on the Game Boy Advance. So shouldn't the GBA game have its own entry as an enhanced remake?
And here's the part where we debate the extent of the changes -- new playable characters, new levels, new music? Then you get authorized to make a new game entry with a new, written by you description, and the GBA information gets moved there.
Well, we have
- general overhaul of graphics
- arranged versions of the 8-bit songs, and a few new songs
- a new simultaneous four-player mode (NES game was single player only), I think this the most notable change besides the visual and acoustical overhaul
- no entirely new levels, but various level design changes here and there
- three new mini-games for up to four players
- a new secret playable character who is unlocked last
- various smaller changes, like a few control differences for the special abilities, differently sized bosses and a few enemies got changed
This should definitely be split. We have a dedicated gamegroup for such titles, and there's definitely more than enough new in this game to warrant its own entry. :)