MUCH better than the reviews say. Although it has a short storyline, swinging around is just plain fun!
Graphics: Excellent, except for the occasional time when the framerate slows down. It's not enough to do much, as it's only for half a second, but it is noticeable. The characters have been kicked up a notch, and look great. Also, when you are swinging really high, you will notice that distant buildings will lose their textures. It's not any different from the other spider man games, but it can really make you think, "Okaaaaaay..."
Sound: All the spider-man movie themes you've grown to love. Bruce Campbell makes many more comments than ever before; he really went all-out in this game. Believe me, it's a good thing. He turns times when you can be frustrated fighting into a laugh. Also, the whole cast is here to voice the films. The voice overs are what you'd expect, and J. Jonah Jameson still manages to be hilarious in the cutscenes.
Value: With a couple of unlocks and things to find, this game will leave you playing WAY after you finish the game. Also, you'll continually put this game back in the Wii just to swing around.
All in all, it's a great game that has not been getting the reviews it deserves. The controls are extremely fun and intuitive, and that's what separates the Wii from the Xbox 360/PS3/PC version, not the lacking storyline or graphics. If you didn't love SM2 and USM, rent it first. Otherwise, do yourself a favor and ignore the reviews for once. You'll be doing yourself a favor.