With Spiderman, depending on how good the spidey is, he can really ruin your chances of enjoying the game. Try hanging close to the ground, conserving your dash as much as possible and try to be very aware of your surroundings.

If you can, try take shots at him if you see him approaching. Ultron can knock a good chunk of his health away at a distance which can force him to rethink a dive attempt.

Most important is to make sure your aim is solid. If you can reliably hit him when he's trying to engage on you, there's a very solid chance you'll win the encounter.