First of all, congrats on your first ever finished game!
I like the gameplay loop: kill enemies, get blood, restock your stuff, keep going. I think it would be interesting to have some kind of way to see how far you've got (maybe an extra text at the game over screen to say you survived for 10 minutes or something like that)
The barriers were a nice addition to the game, they helped a lot fending off the enemies. Graphics-wise, I like the look of the tiles and the lighting, it fits the theme of the game.
I think the shooting sound was a bit too loud and raspy (I don't know if I'm using the right word, but I mean a bit scratchy), but nothing problematic.
Had fun playing it overall! Good job!