It is! Fun little short game. Would have been nice to have some indication about the health of the player/troops. Also, sometimes it felt like the troops' shots aren't doing anything to the zombies. And I think zombie deaths could be made to feel more impactful, as it is it kind of just changes into a death animation and that's it. Maybe I would add some blood particles or something else that would make the zombie death stand out more.
I liked the corridor-shooter idea and that you can give orders to troops.