Well, it's not really an issue, persay, as much as it is a little nuance that's kind of annoying. Why do each of your missile and bomb upgrades automatically replace your old ones? I didn't see any problem with the way Super Metroid had things set up, that is pressing Select to toggle between missiles, super missiles, bombs, and power bombs. Seeing as the Select button isn't even used in Metroid Fusion, what was the problem in reusing the same feature? It's just a little something that was slightly offputting that I was wondering about.