-Thunder Cannon/enemy projectiles can be seen through doors. This is a bug inherent with the engine I'm using and short of getting my hands on the source code I can't do too much about it.
-Thunder Cannon projectile will not hit enemy if door closes in line of sight of enemy. I am unclear if this applies to enemy projectiles but it doesn't seem like it. Pretty sure I'm still taking damage from them even when the door shuts abruptly in my face. This is again related to the bug in the engine mentioned above.
-Certain environment sprites do not allow enemies or the player to fire through them even though they should be able to. I've been working on this.
Feel free to add anything you might find so that I can slap the hell out of it.