One cutscene and significant disarming later, you're ready for the last stretch of this level. Problem is, there's quite a bit more level to stomp through, so make sure you've got some time to finish off the whole chunk. As you might expect, the next area is another battle playground, ready to be blown apart in no particular order. Instead of bugs, however, you're dealing with human enemies again, and that means enemy Suits. There's one available right away here, and if you're good, you can finish a large portion of this area with it alone. Just be aware that this long street leads to two points of interest - an overpass hiding one VS, and a heavily guarded cache of weapons and tank Suits at the end of the road. As before, keep your aim focused entirely on VS legs and you'll do fine. In fact, with the VS shotgun, you should be able to down enemies before they can even get one bullet out.
When you're done clearing the end of the road, look to the southwest. Down below you'll see a bridge running across a sea of lava. More importantly, you'll see the "N" token spinning on top of one of the metal sheets. Shoot it, then head back up the road toward the overpass you went by earlier. Activate the post, grab the extra rockets and look east. There's a VS sitting on a tower surrounded by lava. Just fire off two rockets at its legs to push it off into a hot, liquid-y death. Directly underneath this stretch of road is the "A" token - hop down, turn around and venture into this western assemblage of metal beams and snag it. A high-jumping VS makes getting into this spot a whole lot easier.
At this point you'd be better off securing the high-end VS found in the westernmost hangar. There's another VS guarding this bridge, but it's best to run past and lob rockets at it from the other side of the river, pushing it into the lava like before. If not, get on the bridge and chuck some grenades onto that platform to rip up the VS' legs real good. Now, with your fresh Suit, head back east and down the tank VS waiting for you in the long hallway. Beyond here lies a pretty straightforward path to the boss. Keep an eye on your energy, avoid energy-sapping weapons (like the ones your present VS have) and press on. There's another sleek 'n' sexy VS in a large room ahead with two Suits guarding the area. Take it, go to the next room and hit up the data post. Make your way straight ahead, up the large ramp. To the right you'll see two large fans - the second one is hiding the last token. Peer inside, collect it and move on to the almost-laughably-oversized tank boss battle.
This thing... is a pain in the ass. Period. We've fought it plenty of times and still haven't found the super-cool-ain't-this-easy way to beat it. The best advice we can offer is to use the many Suits at your disposal to deal tiny bits of damage until this pile of junk dies. The smaller tanks can be dispatched by simple human rocket fire (it's best to save the big guns for the actual boss), as can a series of tubes along the perimeter. If these falling pipes serve a purpose, it's a mystery to us. The oversized tank can transform like its smaller cousins, and this is when it's the most vulnerable. This form shoots off special rockets that slowly take pieces of the floor away, revealing a lake of lava underneath. It's possible to lure the tank into the lava, but unless you really get it stuck, it'll just climb out. The grenade launcher found here deals the most damage, so if all else fails, grab it and fire away. Patience will win this one.