Cool little game, I really liked the art of the sprites. Would be cool if all the environment was hand-painted, that would really make the game stand out. The pistol fire rate upgrade made me laugh, really OP stuff! :-D
The Unreal Engine here is a really huge overkill. If you made it in Godot, or even Unity, the game would have like 10-15 MBs and wouldn't eat 70 % of GeForce 4070 Ti and 50 % of 20 core CPU :-D It also asked to communicate on the private network which was really suspicious but it somehow worked without it when restarted.
But I understand that sometimes you just want to try and learn new cool things :-)