Getting some Nitemare3D vibes here. Very nice. There's a surprising amount of monster variety and enough guns for a game this short, although I'm not really a fan of having straight up upgraded versions of the same weapons. The sound department is somewhat lacking, and the lack of feedback when you shoot the enemies makes the combat feel a bit unsatisfying sometimes, especially when fighting enemies with lots of health. Other than that it's a really solid game - and runs well on even ancient toasters. Great job.