It was a bit of a challenge to add that upgrade system mechanic but its something I wanted to work on learning so I threw it in despite the trouble it would cause haha. Wanted to make this small game a bit more fun so I gave it a shot. Hitboxes definitely could be better with tweaking of turning the hitboxes on/off at certain times and I plan on working on that eventually. It technically IS possible to avoid damage from the large skeletons (attack them as early as possible before they hit you) but its not totally obvious to the player so that's something I need to tweak and work on to make the experience a bit better. Thanks for the kind words about the models, animations and music choice!