Okay, yes, the controls aren't entirely aesthetically pleasing and even clutter the screen. I'll keep that in mind.
Regarding bugs, it's likely a problem when transferring the project to other computers, as I've tested it and it's fully functional (at least on my computer).
Regarding the shop menu, I tried to make all menus accessible with the keyboard and mouse, but I didn't have enough time. At least it's something that can be fixed, and thanks for checking it out.
Yes, the damage effect isn't entirely visible to enemies. Originally, they were going to be something else, but I ended up making those sprites. I don't want to change their design colors, so I'll look for another way to make the damage more noticeable.
Thanks for the comment. This gives me an idea of what to work on first.