This is great - I love the enemy animations (both their waddle and when their heads get lopped off). I also really love how there are certain rooms that lock and force you into a curated combat encounter. Very Doom-esque in that regard and I think makes it stand out because then you were able to flex and design a well paced fight.
I also love the secret walls. And the armor system is a nice addition. Overall, really well thought through and solid game! One note is that I think you can take away the first locking door because if you walk past without picking up the sword, you can't advance the game because you can't go back and pick up the sword.
Great job!