I'm not sure if anything can save Metroid at this point. The low initial sales of Other M imply that there was a lack of interest upon release, not just because the game was terribad. Now maybe, if they figured out a way to preserve the core metroid tenets without discouraging newcomers with the obtuseness the series usually carries, they could make it work. Prime 1 sold as well as it did due to a curiousity among new players but you can see that subsequent versions never hit the same mark in sales. I see these as folks who probably got frustrated and therefore ditched the franchise. I also think they should seriously consider some form of multiplayer at this point. Nintendo's co-op/multiplayer games are among the most lucrative for them, and it could draw in folks who normally wouldn't pay much mind to a labyrinth shooter adventure thing. I think it would have been smart for Retro to give their engine to NST and have them develop a companion multiplayer experience for Corruption. Hunters multiplayer had many interesting ideas even if it wasn't the best realised experience.
