And edit on what i said last. you only need to unload at least one shot for the game not to crash. the game had a problem dividing zero by zero before. because you shot zero bullets and everyone was dead.
I just found out that if you unload all the ammo in the gun you start with on case 6 thaen the game doesnt crash at the end of it. but case 7 is completely black. which is more of a problem,
You can sit at the chair in the room after the tutorial. after a bit it opens the the mission brief and you click to unlock the next mission. This will get you up to case 6. but the game crashes right after that level. This needs fixed because this is an absolutely epic game.