On Board the Sword
This mission takes to the fight to Kang's flagship.
You'll arrive and be instantly attacked by almost completely harmless goons (there is one ninja in the mix). Smash 'em up.
You might take special note of the holograms here- there's a prize for destroying them all, and you'll likely destroy at least one here as collateral damage. They're on the left and right sides of the corridor.
When clear, laze open the gold box by the far door.
Build a grav booster with the parts, and bomb your way forward.
This takes you into the main hangar. There are a lot of forcefielded baddies here- you can kill them by egging them into attacking you, then striking when their shields are down, but it's quicker to only attack the ones directly in your way as you take down the generator.
That turns out to be a three part process, only two parts of which are easy. Part one is to laser open the gold panel stage right of the generator, ground level.
Assemble the pieces to expose one of the three generator panels.
On the stage left balcony, use Spiderman to yank a panel set in the sloping ceiling.
Toss a grav bomb on the revealed booster to expose the second generator panel.
When you do this, two guards will emerge from a nearby guard station. Smash them.
The button inside their guardpost is actually a teleporter. Pass through it as Spiderman or Iron-Man, then smash everything inside the destination room to build a console.
This console allows you to rock the ship from side to side. Choose 'left.'
The camera will show this maneuver to have cleared a crate on the lower level. Go down the ladder that the camera indicates, then smash and assemble everything in this room.
This creates a barricade robot. Switch back to your character in the console room and tilt the ship right. This slides the crate/plug into the center lane. Push it upstage to the port.
This unlocks the final panel. Return to the generator and use Iron Man to blast the exposed golden innards to destroy it.
Now you can mop up the remaining Kangbots (plus a fresh wave for luck), including the one guarding the control room on the upper level, upstage right. Use the console in that room to access the monorail.
Have Spider man pull open the monocar door, and dispose of the very-unscary minions within.
NOTE: Make sure all three pretty members are nearby, with their feet on the floor, before you board the tram. If they're not, they may not seat themselves properly, the game will become stuck, and you'll have to do all this again.
The tram will take you the bridge, where you chat with Kang and fight with Korvac.
Korvac's never-ending barrage of cosmic power can be a little annoying, but a good character to deal with it is Spidey. He tends to automatically side-step incoming fire, allowing you keep up your own barrage of webshots.
As the fight goes on, Both Kang holograms and Krovac will fire beams at you- just dodge until Korvac's shield drops again, elbow aside any local goons, and keep up your web-attacks. Toward the end, you'll have to chase him up a balcony to do so.
His defeat completes the level.