Can a great game be ruined by bad controls? I think so and Geometry Wars: Galaxies is my example, on both Wii and NDS. The lack of two joysticks destroys the game.
The Geometry Wars games are a series of great retro twin-stick shooters, a sort of Robotron spiced up with high-def graphics. Galaxies adds a lot of depth to the previous incarnations and I was greatly looking forward to playing all the different game modes.
Sadly, my attempts to play on the Nintendo DS quickly ended in hand cramping. The default controls are left hand holding the NDS up and working the D-Pad, right hand using the stylus to aim your shots. It works OK but holding the NDS up is fatiguing. The Wii is even more disappointing. The controls have you moving with one joystick and controlling where you shoot by pointing the remote at the screen. But the pointing is too imprecise to work. And it's awkward in that one hand is doing something abstract (moving a joystick) while the other is doing something fairly literal (pointing at screen).
I gave the game to three friends for Christmas. Not a big success with anyone. My eleven year old nephew liked it ok on the NDS and didn't mind the controls, but I think he got bored of it quickly. My friend Marc didn't play the game on his Wii very long; it's a more demanding hardcore game than they prefer to play and the controls didn't help anything. My other friend Mike is more of a gamer nerd and wasn't turned off by the hardcoreness, but also agreed the controls were awkward. He went so far as to buy the dual stick controller for the Wii, but that doesn't quite work either because the physical hardware design forces the joystick into the eight compass directions rather than allowing smooth 360 degree motion.
I still think Galaxies is a very good game, it's too bad it's hamstrung by being a twin stick shooter released on Nintendo platforms that don't have two joysticks. Particularly since Nintendo has made a name for themselves in having games with innovative controls.