Ok, first off, I love your videos about game dev. As an aspiring game dev as well, I think it's really cool how you're dedicating yourself a lot on this. But I'm not here to talk about that. This game is amazing!
Music - 9/10, really feels like I'm a medieval dude killing a bunch of monsters.
Art - 10/10, a charming art style that really sucks you into the game world.
Gameplay - 8/10, fun gameplay. Psychics is absolutely amazing, however it got a little boring and stale toward the double digit waves.
Now for some problems I encountered and things I suggest to improve this game:
1. Enemies would hit me when they were outside the little walled sections and I was inside.
2. Game doesn't really pause when you hit pause. When I hit pause, I noticed that the only things that happen is that the enemies and you stop moving, but you can still let go of and shoot stuff. I think you should use get_tree().paused = true/false when they hit the esc key. Just don't forget to turn the process mode to always in the Control node.
3. I didn't really know when I got hit. I think maybe you could do a screen shake effect so the player really understands they got hit.
Other than that, this game is absolutely amazing for being made in 2 weeks. Can't wait to see what else you're going to make!
P.S here's a picture of the pause script: 