@Pheno I understand where you're coming from. The intention was to keep the player characters at a low level of detail and size so they could be more easily animated in-game, while the enemies would be static sprites and thus given more detail to work with. Since the screens aren't animated this is sadly a moot point, but a good frame of reference for this dichotomy would be games like Romancing Saga III or Final Fantasy VI on the Super Nintendo. The GBC aesthetic of the upper-screen characters is probably what prevented them from being considered as unfinished and thus redrawn.

Good sprites though the enemys should have the same number of colors so they look similar

I think there's a bit of a dissonance between the graphics for the characters and for the enemies. To me this is especially obvious with the first screen, because the player sprites are very simplistic and look geared toward a GBC sort of aesthetic, while the boss they're fighting is vivid and anti-aliased and looks more at home on a DS game. Neither of these are inherently bad, but when looking at them, I can't help but think that the player sprites look unfinished.