Swinging around the city, the story, the characters, the visuals, it all comes together to make a pretty fun game.
Unfortunately, Ultimate Spider-Man is plagued with problems. Many of them are major problems, and taken as a whole, they really diminish the appeal of the game.
The gameplay of Ultimate Spider-Man takes place in a free roaming city map, much like Grand Theft Auto. You can freely explore the city, doing some side missions, or you can go to the next story mission, which advances the story. The strange thing is, while the side missions appear to be optional at first, they're actually mandatory. You have to beat a certain amount of side missions before you can move on to the next story mission. The developers did this to extend the length of the game, as the story of the game is painfully short. A lazy move on the part of the developers, and it hurts the quality of the game. Besides, even with the mandatory side missions, it's still a short game. Barely 10 hours.
The Venom missions aren't nearly as fun as the Spider-Man missions. Another Marvel-based game, The Incredible Hulk: Ultimate Destruction, came out around the same time as this game did. I would've liked to see Venom control a bit more like the Hulk did in that game, because that game was a lot more fun. Venom's missions make up almost half of the story missions in the game, so the fact that he's not too fun to play definitely hurts the story missions.
Another problem I have with the story missions is the chase missions, where you have to keep up with an enemy as they fly through the city. The ones where you play as Spider-Man are OK, but the ones where you play as Venom are horrendous, and should've never been in the game. The chase missions are unnecessarily difficult, especially the ones where you play as Venom.
The combat is subpar. There are a few web moves you can do, which are nice, but the hand-to-hand combat is basic and kinda boring. Plus, you're always fighting huge clusters of enemies who gang up on you and drain your health, so you have to take advantage of the weak AI and get a few of them stuck on the scenery so you can divide and conquer. It's boring and it takes forever, but that's the only way you can get through some of the beat-em-up missions without dying.
The missions where you save people are the best part. They're pretty fun, and some of them have button mashing minigames which are thankfully easy. The boss fights are kind of a mixed bag. This is the one area where I think Venom is more fun to play than Spidey. Some of the boss fights are intuitive and fun, while others are boring or overly frustrating. All in all, the boss fights are okay.
All these flaws are glaring. But even with all that said, I think Ultimate Spider-Man is still worth a look for Spider-Man fans. You can probably still get enjoyment out of it, even if it is a slight disappointment. The fun of swinging around the city, the story, the characters, the visuals, it all comes together to make a pretty fun game, despite the problems.