If I ignore everything about Other M that I absolutely hate (the story, the writing, the pixel hunts, the forced item progression, the fact that you can't 100% the game before facing the Queen, the WORST FINAL BOSS "FIGHT" OF ANY GAME EVER, etc.), I like the game. The gameplay is generally surprisingly good.
I genuinely believe that Other M is meant to replace Fusion in the mainline continuity, though. I honestly do. There are lots of reasons for it, and I'll be writing about it for a feature this month. We may also debate it on Connectivity.