This game was truly entertaining. That said, I think that the extra levels were detrimental to the game without having any new enemies or threats. I understand that the time constraints of the gamejam play a role, but I believe that would be the most "actionable" improvement you could make on this game.

Ok, This game was actually quite good :)

The visuals are nice, the sound is good, the controls are great.  

Having a destructible environment is really nice as well :)

It's just that my mouse-finger starter to hurt quite badly from bashing the shoot button all the time :P  Maybe add an automatic gun or a hold to shoot option :P

Also, something went wrong with the last mission, I read the whole plot and when I wanted to start the mission I got the fail screen and got booted back to the start screen.