There is a new Build engine game. It is called Shaw's Nightmare. It uses the classic Build Engine by Ken Silverman.
You are Shaw. You were reading a book then you fell asleep. Suddenly,
your headphones start picking up strange sounds: static, men yelling orders,
screams, bones cracking and finally silence. Then a hole grew and you are
sucked into it.
Things aren't looking too good. You have never been alone in your life.
Plus you don't have your father's guns. If only you could get a hold of a
rapid catapult or a camera gun, you could protect yourself.
Suddenly a scout boy comes and you stabbed him with a nearby knife. Then
angry growls arose. They know you're here. There's no turning back.