I did not buy it, so I can't comment on the gameplay save that it wasn't compelling enough for me to buy it and I felt the story was unnecessary compared to story-minimalist games that emphasise the player 'being' the main character like Metroid Prime.
However the sales were a failure compared to what Nintendo needed. A Metroid Prime sequel would have sold more (especially in Europe), and a 2D Metroid would have cost a LOT less (and sold better in Japan). Either would have made more money. Other M certainly did not push hardware, that is its biggest failure. The game that seems to be holding up the Wii this holiday is NSMB Wii, not SMG2 or DKC or Other M like Nintendo wanted.
And the music was a failure. Compared to the amazing soundtracks of Metroid, Super Metroid, Metroid Prime and Metroid Fusion this was ambient, unmemorable and bland. The music is the part of any videogame that I look forward to the most [I decided not to buy Epic Yarn, DKCR or Pokemon B/W purely based on their lack of good music].
My suggestion for Nintendo is to try another 2D game that is nonlinear like the original Metroid. The last few games (Fusion, Other M, Prime 3) have all been so linear in progression they feel like a chore to complete.
