Compared to the original Metroid II, the changes it makes are both good and bad. As for the good changes, the addition of teleport stations helps a lot with backtracking, the scan pulse is really useful, the Omega Metroid fights are a lot better, and the parry is fun. As for the bad changes, the 2 new main bosses pad out the game a bit and feel unnecessary, the Gamma Metroid fights are annoying and have unnecessary extra phases, and there is a bit too much backtracking for optional items. Samus Returns fixed some big issues of the original for me, but also introduced a couple of new ones.
Final score: 6/10