This was a wonderful game! I really enjoyed the speed that the character runs, but I will say that the gravity is really fast and sometimes feels unnatural. I also had issues with the spikes being very unforgiving and hard to see on the background. I also found that full screen lets you see more of the game which was super helpful when platforming around. Last critique, I think the game would immensely benefit with controller support.
Otherwise, the game looks and sounds great! The pixel art is really solid and the animations are clean. I really like the main character herself in terms of design and changes she goes through in the game. The music was also straight up amazing!