@theRepublic, it makes me picture Samus in combat, and the way she fights in Other M is more like what I pictured than the way she fights in the prime games. Besides, I played Fusion and Zero mission first so I missed the acrobatics, shooting while climbing and the fact that I could see samus when I played Prime 1. Glad to have that back in Other M.
@Gumby, just got to the part where they partially restore a computer and discover that the Galactic Federation was illegally experimenting with bioweapons. They split up to search for further intel, I hit the save room and stopped playing. OK, there's no exploration, they even lock you out of previously accessible areas, but there's still hidden upgrades and that was the most important aspect of the exploration to me anyway.
Yeah, I'm guessing they were a bit to scared people would get lost in the game if they left the areas openned, but all areas unlock when you finish the game.