It's not too bad - but i did prefer the older games; the swinging mechanic in this game doesn't latch on to actual buildings like it did in Spider-Man 2, it kinda just uses the height of the buildings as a guideline, so you can still being swinging from thin air. Another not so great thing is you don't get any random crime encounters, which kinda takes away a little of the realism for me; Other than those little things, it's a brilliant game, it's got stealth bits which are fun, and the 'web rush' ability that you have from the off is kinda like web zip coupled with bullet time - it's an awesome feature! The animation for swinging (apart from what I mentioned) is great, loved the acrobatics and stuff.
Basically; coming from a marvel nerd, it's not the absolute best game, but it is definitely worth getting!