Awesome / Grey Goo (2015)

• The first entry under Nightmare Fuel, above? You can do that in-game. The Dweller is an ambush unit, waiting underground for enemy forces to get close. First, it explodes to take out the closest units, then it reforms as a Blob Monster to mop up whatever's left.
• Pretty much the entire soundtrack. Especially the ones that sound more like a last-ditch attempt of desparation in a hopeless vain attempt to stop the upcoming annihilation of all life. This is your last stand on this rock. And if you don't stop them here? Everyone else dies.