This is another easy XP cheat for level 10 Reclaimed.

When the third AA gun has been taken out, you will progress through to a building that has been destroyed. You'll know when you're at the right building because the floor will be destroyed also.

When you get to the exit door of the building, stop. There will be a big drop and through the exit you should see a large open area.

In this area, there will be heaps of aliens spawning... in fact unlimited aliens!

The best way to take them out to to look to the far right, equip something with a scope, and then pick them off as they appear above the spotlight you'll see.

As long as you stay inside the building and don't drop out of the exit door, then the aliens will keep spawning and you can keep killing then and racking up the XP!

When you run out of ammo, just reload your last checkpoint.