I think Other M just had too many things going against it.
First off, the method of control that was chosen for this kind of game was just ridiculous. I mean, having your controls restricted to only the Wii remote? Really? The devs must've been smoking something when they had that idea. Just a few years prior we were playing Metroid games with the Nunchuk, and that worked just fine(I think so anyway). Could they not find a good way to utilize it in Other M?
Gameplay elements like the main "method" of obtaining suit abilities was just out of the blue. Samus refusing to use her suit's functions because Adam hadn't yet authorized it doesn't exactly mesh with the typical Metroid style. It seems like the reverse, actually. You need the abilities TO destroy the bosses rather than beating them down then claiming the rewards, then using the newly acquired items to further explore and progress through the game.
I'm not a big fan of the whole "authorization" thing the game had going for it. I get why it's in the game, but IMO a better explanation would be if the space station they were on had various force fields that disabled certain devices that Samus had to find and turn off in order to get her suit to full power. Plus that would have added an exploration element to the game instead of making it a linear path with the occasional dead-end hallway to the side.
This seems somewhat arbitrary, but you're right, it would provoke some sense of exploration, because that's one of the primary themes of the Metroid series. Though I prefer the idea of something happening to Samus which causes her to lose her equipment(which happened 3 times at least), and she has to track down her gear(along with some new stuff). I think it plays to the strengths of the exploration factor better. The whole "Not authorized" thing just kind of kills that aspect of Metroid.
Once of the worst moments in the game is that infamous flame-suit scene. The one where Samus is in a burning hot area but won't activate her suit's fire-retardant features because Adam didn't say she could. It characterizes Samus as a blind idiot who won't even protect her own life unless Daddy says it's okay and it characterizes Adam as an ******* who doesn't care about Samus' safety.
Throughout the whole story Adam just sort of pushes Samus around, and she just takes it. And we're supposed to believe that Samus thinks of him as a father figure? Anyone who didn't know any better would probably think she's a glutton for punishment. And about the whole PTSD thing....what a load of bull. Samus is the baddest bounty hunter this side of the universe, who does the same thing when faced with any of the big bads out there: Point her Arm Cannon at their faces. Samus really shouldn't turn into a scared, confused child when confronted with Ridley.
Not to mention that the Metroid timeline goes like so:
Zero Mission -> Prime -> Prime Hunters -> Prime 2 -> Prime 3 -> Return of Samus -> Super Metroid -> Other M -> Fusion
This mean that, canonically speaking, Samus had fought Ridley four times prior to Other M. Then, when she finally thinks she kills this ******* for good and has avenged her family, he comes back again. At that point it's completely understandable that she'd break down under the mindset that no matter what she does, she cannot win.
Wouldn't that be five times, then? Or are you counting both of the encounters in Corruption as one battle against Ridley? Anyway, at this point one would think(I would) that Samus would view Ridley as a routine job now, and that she would put him down as many times as it takes before he's gone for good.