Fun little game. I particularly enjoyed the recoil and SFX of the weapons which have an almost Duke Nukem feel to them. That and the explosive effect they have on the bodies of 'enemies'. 

SPOILERS!

Fun right up until the point when I realised they are not going to harm you in any way. They're just random terrified dudes going about their day and you're some crazed lunatic who has gone postal.