love the music. though gameplay is a bit bland, 30 or so hours isnt really enough for to develop a game though.
i thought i would try leave 1 alive to see if he would do anything, he did nothing. not even sure if its possible to lose. and as people do occasionally spawn inside you it might be possible to win by chance with out touching the controls.
i would suggest some improvements. but with the limited time theres not much i could think of without altering the base gameplay, apart from making it a larger area to make it harder get the people and perhaps some of the visual presentation, like effects and animations.