The bad news is the controls felt really janky, boss did hit me even when I launched him in the air and cancelled his attack animation. I could only doublejump right after the initial jump, usually you can do that right until you land. First boss shooting was barely telegraphed yet instahitting.
The good news is you're using Unreal Engine so you're on the right path, man. It's difficult to learn but very rewarding in the end. Liked the overall visual style, though perhaps some lighting and shadows won't hurt too!