I played the First Level and the second one, and I think you have to rebalance the weapons or change the enemies AI, because ,from all the weapons, I only used the handgun and it stuns the enemies very easily, I can take the handgun, walk in front a enemy and shoot it in the face and he will not do anything because it's stunlocked, this makes enemies really easy to deal with. The only enemy that made some damage are the dogs because they are fast and don't get stun. Also it's fairly easy to outrange the bad guys to the point that, you shoot at them but they only keep walking at you trying to get in range to shoot at you. The guy with flamethrower is slow and easy to outrange too. In the current state, the game is very easy by exploiting this weakness.
As final conclusion, I think you should tweak the enemias range and walk speed to make then more of a threat, and maybe reduce the stun of enemies.