Hey! Your mobile controls work well. It was a good idea to implement a joystick for moving and for aiming although I still suck at both haha. It can also be hard to avoid the enemies. I think the collision boxes on the enemies should be reduced so that the player has more leeway to maneuver the map since it is already small. At the moment, I'm unable to make it to the shop. I simply can't kill enemies fast enough or I don't have enough health. I noticed that different drops give you different amounts of money as well which adds some nice extra incentives for the player to go after the good drops even if its puts them in a risky situation. I think you could done more with your UI as well even though it works as it is. Maybe You could of designed another level just for looks and put it as your background for the menu. Overall, your game works great and is a neat idea with the waves of enemies!