As much flak as Other M gets I can't say it was a bad game, gameplay wise. It had tight controls, neat abilities, and a generally good sense of exploration.

Just the story and characterization is what doomed it.

Actually, the controls were pretty awful, thanks to an insistence on a really dumb control scheme that also forced bosses to have huge, telegraphed "It's OK to take your time to switch to missile mode" pauses that broke gameplay flow and the natural feel of finding moments to exchange shots, and the similar "dodge" button that makes you invincible even if the pre-rendered dodges throw you directly through the enemy.

Again, it always seemed like they were handed an excellent, working formula in Metroid Prime, and they decided they were too good for that, so they wanted to ruin everything that made that series great to prove it was their series to ruin if they wanted to. (In fact, one of the things I remember reading was that we had Retro Studios to thank for the Wii shipping with the nunchuck instead of everyone having to pay extra for them and Nintendo forcing most games to rely upon the Wiimote and their hideous motion controls, exclusively. They basically demanded we have an actual analogue stick and enough buttons to play a REAL game, and Nintendo eventually caved because Metroid Prime 3 was by far the best launch title they were going to get - not counting Twilight Princess because that also came out on Gamecube and the Gamecube was a superior version because it didn't have the hideous motion controls that made the spin move impossible...) The Other M controls made the game feel far more formulaic and gamey and drained any real sense that it was a proper Metroid game out of it.