Very nice, I like this one.
Action real time roguelike is a very interesting and often undervalued unexplored territory in my opinion!
I don't like much the left side of the map, yeah it's cool to discover an unexpected zombie near the corner and then shoot/flee but searching for that last zombie left becomes a little frustrating sometimes.
edit: I just noticed the map changes every game you play; in that one there was an intricated labyrinth on the left side. Why doesn't the map changes every level, instead of changing just every game?
I think this game has potentials, it would be cool to see other weapons like shotgun with short range multiple shots, machineguns or rocket launchers capable to destroy environment elements.
Good job.