Gave it a go, the resolution problem is a big one at the moment.
However, if you made your own assets, the tilesets seem pretty tidy and UI has contrast while being colourful and "usable" (I died before being able to use the potion UI and the rest was hidden due to scaling issue).
Once you fix the Camera and UI, the only things I think need work based on what I could see, are the bullet speed and I feel like for this kind of speedy dodge and shoot game that it would feel nicer if the character sprites had animations.
Thanks for making it.