Hey there!
First of all thanks for playing our game and giving us valuable feedback. That's always the best for us. The graphics were very, very important to me and Emily and that's why we put a lot of time into it and day/night shifts as much as possible, so we really appreciate that feedback. :)
We also had the plan to make more variations of the guns, more upgrades but you know, GameJam, only ten days and a week with fulltime-job in between. :D
The Screen-Capture thing we've noticed aswell and also thought we fixed it but some people still seem to have the problem.
The Enemys behind the door I've noticed aswell but haven't had a deep talk with the programmer about that for now, since it's voting period but we definitly going to check that out.
For the performance problem we also uploaded a Windows version ( yes for Jam Games sometimes annoying to download etc)
But we really value the feedback and thank you again! :)
Wish you the best!