I exchanged my initial purchase of Rayman for Red Steel.
I spent a good hour playing Red Steel on the first night. Got to be honest, this isn't a groundbreaking FPS by any stretch of the imagination. However, its not a bad game if you are prepared to take some time to get used to the control mechanism, which, coming from an ex-hardcore PC FPS fanatic, is much more familiar to the faithful mouse and keyboard, then a gamepad ever was/is.
So in terms of graphics it won't blow you away, but if you want to perfectly demonstrate what the Wii has to offer in terms of alternative and unique control mechanics, this is a perfect example of what is to come, and quite frankly, the future is bright for the FPS genre on the Wii.
One more thing I would add. If you were a massive fan of the classic N64 game Goldeneye, and wiled away many a wee hour playing it multiplayer with your mates, then you MUST get Red Steel. The multiplayer aspect is SOOOO reminiscent of Goldeneye you'd sometimes lose yourself wondering whether you'd stepped back in time to those good ol' days!

Definitely worth it for the multiplayer aspect.