We just got back from a marathon gaming session, and Metroid was one of the most interesting titles that we played at Nintendo's super-secret, invite-only gaming session.
Metroid Prime 3: Corruption Definitely stole the the show. The graphics looked amazing -- better than Halo 2 on the Xbox without a doubt -- and the levels showed off sparkling details, proving the Wii is far more powerful than the Gamecube. Out of all the games we played, the Wii controller seemed most at home with Metroid.
You don't fire with your index finger, but with your thumb (using the A button). This sounds a little goofy, but in practice it worked very, very well. You could press the directional pad to fire rockets or enter your scanning mode, and the trigger (aka the B button) handled jumps very nicely. Samus has a few new moves that take advantage of the motion-sensitive controller. By locking onto a target and thrusting the left nunchuku forward, Samus could launch a grappling beam. The beam is similar to Half-Life 2's Gravity Gun, but was mostly used to push rubble out of the way, open grates, or in a nice touch, yank shields from enemy hands. The other major Wii functionality was that some control panels needed to be lifted, rotated, and pushed back into slots -- these movements were all handled on the Wii controller.
Aiming with the point-and-shoot controller felt very nice, though it took a few minutes to become truly comfortable. The experience was much like playing a PC first-person shooter, especially since the nunchucku analog stick controlled movement We found that standing roughly four feet from the TV provided the best motion, and the cursor stayed smooth and steady -- no shakiness! The frame rate was also smooth and consistent, even when the screen got crowded with special effects.
Metroid was probably the best Wii game on display. Wii can't wait to play more!