Meet new levels in the revived Quake, it's called Quake Renascence. You are a soldier who will face an unknown alien mind. The enemy is clever, strong and looks terribly externally. Reasonable monsters are an explosive mixture that can not be easily defeated. Do the assigned missions and destroy the terrible creatures, wandering through the confusing mazes. Wait for aliens from intergalactic portals, so as not to be caught unawares. The enemy will not give you a chance if he attacks suddenly. Change weapons as necessary, not everyone can kill monsters with brains.