I finished Metroid: Zero Mission on a plane today. As it turns out, there's a whole extra part on top of where the original game ended. I knew something was up when I went to fight Mother Brain without the power bombs and two or three other suit upgrades. Anyway, now I get where the titular heroine is derived from when she makes her appearances in other games.
I was pleasantly surprised by the bits at the end, but I'm glad the shift in gameplay lasted only long enough to make you glad to get back to the norm for the finale.
I wonder how Metroid: Other M is shaping up for Wii.