I encountered two bugs that made it impossible for me to finish the game:

1. When I load the latest checkpoint the flamethrower is removed from the inventory making it impossible to get past some barriers that need to be set in fire.

2. Many times the walls, floors, etc. failed to render. I could see skybox and the NPC's floating in the air but that was it. The fact that this happened in the same place every time made it impossible to continue.

I hope they patch these soon...