For sure a good game for only a week to do it, but it feels very unresponsive, lacks feedback for the player and sound effects overall. I would also change the default mouse cursor into some sort of crosshair to indicate where are we aiming. I also had some troubles with the health rewinding for some reason.
While I appriciate how well the game is made, and I see a lot of people are really enjoying the "Cupheadiness", hope nobody will take it personally, but to me it's a little bit over the line, and could really be called a rip off, when it's paired with mickey mouse it really starts to go into copyright infringement teritory. While I understand the game is just made for this jam and for fun in general and not for commercial use, as I said to me that's a little bit too much. I think it also really hurts the game that it resembles Cuphead so much, because while you can appriciate the inspiration or even parody of some sorts, it puts the thought of Cuphead into my mind instantly, and when you compare any jam game to Cuphead, there is no way the jam game would win, so problems with this game are just standing out more by comparison.
After that rant I still have to say that some aspects of gameplay, dashing for example are well made, and both the art and music is really top notch and instantly resembles what it should resemble. Enemy-wise skeletons are my favourite, great looks overall, and also they telegraph their attacks in a very cool way.
I'm sorry if that seemed a little harsh, but I really appriciate your skill, I would just like to see this set of skills used in something more original next time. Anyway, keep up the good work, and I wish you good luck for both this jam, and any future jams.