I needed to build the cube maps though, so just make sure you do that before releasing.
Some general points.
1. It took me a long time to figure out I had to get the barrels to jump the fence. The exploding barrel just inside the warehouse is misleading. It gave the impression I needed to use that to move forward. I would suggest removing the barrel and making it clearer I need to climb the fence.
2. The section with the Hunters is not very well designed. It's too easy to hide in the hallway and keep going back for rockets. I would suggest dumping the player into the area where they have no way to go back. It's tough on them but otherwise it's no fun.