This map is basic, but if it's your first map, then great work! I had some issues though:
1. There's no intro, the player has no chance to survive when spawned.
2. The level design is too basic, every box is placed on a 90-degree angle.
3. Vent is too hard to notice, my friend and I stumbled on it by an accident.
4. We've been stuck on the underground section, until we tried to break the door with explosives, though we expected to have a button like on a surface. Not intuitive!
5. Holy crap, that door is sturdy as hell!
6. The map is *too* short!
I hope that this comment will help you in making the map better!