E1M2
1) Ball scored without falling through net
2) Fake walls view different (It's freq. visual glitch, or may be feature), but report anyway
3) Just small texture overlap
4) I can shoot some cameras, I can see through some cameras, but can't shoot em... Not a bug, but I spent a lot of time seeking for cameras who watching me...
5) Ball can be pushed through semi-transparent ceiling-floor from bottom room with shotgun, but I can't score him from here )=
6) I shot everyone before found way to turn-off field, and two new mobs spawned immediately, feels slightly like a bug, but anyway it's funny surprise...