Hi. Congratulations on your first game!!!
I think it's really fun! good job! aesthetically pleasing, very entertaining, but I found three main problems that are very easy to fix.
1) The enemy colliders are WAY too big, sometimes I lose and I'm not even close to the zombie. One main rule about colliders is that they should be smaller than the enemy/trap sprite. It's better to forgive the players by a few pixels than for them to feel cheated by the game when they're killed by an enemy that's not even touching them.
2) The enemy AI is too simple. They basically charge at you in a straight line even if there are obstacles in the way and they get stuck. I noticed your game is made in Godot, investigate about the AStarGrid2D class, is insanely good for enemy pathfinding and super easy to implement. Now that you're learning, that class is very important and if you pair it with the TileMapLayer it's a powerful and easy way to make games in no time
3) The controls. This will have subcategories, lol.
3a) About the choice of priorities, most people on itch mainly use mouse and keyboard, so I'd suggest you prioritize that instead of it being a secondary option. Once it feels good with M&K then you can move to the controllers.
3b) Aim and fire with arrows and enter... for playtesting is good I guess but the aiming and firing should be done with the mouse and mouse click. Otherwise you're limiting the aim to 8 angles. There are several methods that make aiming super easy, like "get_mouse_global_position" or "look_at" or "move_towards". They're not hard and you don't have to deal with angles and stuff. When thinking about controls try to check other similar games and see how they solved it, Brotato for instance.
3c) There's a deceleration when you let go that makes you rage a lot, mainly if you're navigating the map up or down and a zombie spawns charging at you at full speed it gives you almost no time to react, pairing the deceleration to change direction and the huge enemy colliders... it turns a fun shooter into a rage game, LOL.
The issue here is that all these problems can be fixed in just a few hours, there are no major issues with your game, it has a solid base and can be built upon (like adding powerups, more stages, destructible elements, different weapons, more enemies, flashy animations, bosses, etc...) I really think that if you dedicate enough time it can end up being a super fun (and, hopefully, successful) game.
Again, great job so far! Good luck!