The PC version is the bitter-sweet of the widely released, multi-platformed game. The graphics are by far the best with the maximum settings (although you will need a hefty system to run full anti-aliasing in the wide-open city) but the control scheme is absolutely horrendous. The game was designed for a controller, but translated very poorly to the keyboard.
The game sorta follows certain key points of the movie but then strays way far away with all kinds of villains and gangs. Some of the missions are really boring (i.e. taking pictures) but others are pretty action packed with lots of guys to fight and cool city environments. A new addition to the series is scripted sequences that require the player to push a button during key motions that will help Parker perform superhuman feats. These segments are thrown in to mix up the gameplay and are a worthy endeavor. The missions themselves are introduced by an open-ended option system. You will swing around the city and see icons in key places where you can accept to do a mission. They range in difficulty as well as fun but overall there is a wide variety even if some seem very random.
The combat revolves around button mashing and a few combos that you can unlock. It's not absolutely horrible but it's not anything like we've come to love from the God Of War series or Prince of Persia. Your options are limited though and, again, with the keyboard you end up punching at walls and pretty much everything but the villain you are supposed to be hitting. If you do buy this game you have to go buy a dual analogue gamepad for it to be playable.
The graphics in the PC version of Spider-man 3 are by far the best. If you've seen some of the comments floating around the Web on how horrible the Wii version of the game looks, be content to know the PC version doesn't. The textures look pretty good and the draw distance is quite impressive. I will warn you though that a fairly up-to-date rig will be required to play this game at acceptable framerates on the maximum settings. My computer is only a year old and I was having trouble.
On the audio side of things, it is nothing spectacular but gets the job done. What's most impressive are the actual voices of the cast. The game includes Tobey Maguire, Topher Grace, J.K. Simmons, Thomas Hayden Church, and James Franco. The only major one missing is Kirsten Dunst.
The best part of this game is also the worst: the outdoor web-slinging. It is loads of fun to just swing around the city in total bliss in all its glory for a hours. The problem is the camera system. It doesn't automatically adjust very well and when it does it usually just makes matters worse. So basically you have to use an unoptomized control system to manually correct an unoptomized camera system. This is even harder to do again, with the lack of a control pad.
In the end, this game lacks the uniqueness and polish that would bring it above par. Spiderman 3 is plagued with almost every movie franchise spin-off game—mediocrity.