Right, he can do some stupid shape-shifting BS too... Annoying, and he's clearly got a reason for wanting to fight up close. So there's only one thing to do with this. Quip. And of course, tech.
"Aww, what's the matter old guy? Don't want to play at this whole ranged combat thing? Seems kinda lame to me just trying to blend in with the NPCs. But hey, they're just digital so that's fine! Enchanced recon mode."
His eyes begin to glow, thermal vision taking place of normal as the crowd of "people" is rendered as nothing more than blotches of grey across the field. No heat to speak of, after all, they're just bits of data... His foe, on the other hand, is quite alive. He'd swing across, tracking his foe's heat and quickly pulling up a car from the ground with his free hand. As he passes over, the boy would simply toss it down at his foe's skull.
"Now for step 2."
As the car crashes down, likely crushing a few NPCs along the way. Spidey would keep moving, aiming to go around his foe and around the time the car reaches its target, he'd perch on a building's wall before blasting off a pair of web lines aimed for Janus's back, hoping to slam the man down into the ground with inhuman strength if they hit.
"Hope my little distraction works out, though no telling with this one..."