*An updated version of SM2's swinging dammit. I miss not being able to suspend myself above the street on two weblines, or use a second webline to change my direction mid swing (Like Tobey during the first swing sequence where he narrowly avoids hitting the window/building. SM2 allowed you to do that)
*SM2's ability to tether a helicopter and be dragged through the air behind it, rather than just having you sit on the side of it. Once you tether the flying helicopter, you should be able to gradually climb up the line and reach the side of it. This could be extended to other objects too, like Smythe's flying robots or even boats for some jet ski action.
Smythes flying robots were too easy to webrush. You should be required to be closer to them for it to work, since they are moving objects. Also, moving cars should require you to be much closer to them in order to webrush. All the fun was taken out of car chases by allowing you to jump straight to them from a block away. I always try to challenge myself by swinging onto the roof of the car or jumping to it from a near by streetlight.
*Greater variety of random crimes that are always available, plus more random encounters with enemies and super villains all accross the map.
*Better wall crawling. An option for increased speed, and maybe the ability to decend without changing your orientation (ie. crawl down the wall backwards). I'd like it if you did a 'friction slide' when you stick to a wall while falling or moving quickly, rather than instantly stopping.
*Ground based acrobatics. Handsprings, horizontal jumps and a bullet dodge.
*Improved webrush. More dynamic, variable animations (short distance jumps) and quicker camera transitions especially between surfaces. Also reduce the distance from which you are allowed to webrush enemies and moving objects, as I mentioned with the cars.
*Choice between multiple stealth takedowns. Sometimes I want to stick a guy to the floor, in ASM enemies will actually be alerted upon discovering someone webbed up, this can be useful sometimes.
*An updated form of WOS's webstrike, with a 2-3 person chain limit.
*Ability to deploy webs in the environment between two points. This can be used to create a tightrope (like Arkham city's line launcher), a line for civilians to climb, a means to hold objects in place or it can be used to create a simple foundation on which to create a large web.
*Peter Parker mode with public transportation for instant travel across the map, and the ability to change into Spider-man when out of sight. I actually think a small wanted system (similar to gta) would be good, at least at certain parts of the game for creating some police chases. You could duck out of sight and switch to Parker in order to lose them.
*More involved currency system needed to purchase upgrades and consumables. Some form of limitation on webbing, and a focus on Spidey's ability to navigate without webbing.