Adds a form of artillery that is considerably worse, but available much earlier. Less accurate, less damaging, generally less useful; but also less costly and less hassle to obtain. It won't save you from yourself if you leave setting up your defenses too long, but it might save you a headache if you can successfully crank out a handful of grey flasks between biter attacks.
Mods introducing new content into the game.
Continuously removes biter creep decals that aren't near a biter nest (or the mound of corpses left behind after destroying one). Performance impact should be pretty low but can be reduced further by adjusting settings if necessary.
Small changes concerning balance, gameplay, or graphics.