Aside from the respawn issues after death (which required me to restart the game if I died), the biggest issue I had with the game is the one dan.collings.dev mentions about the camera's position. You had one downward jump that was led with coins, which helped the player assume that is was safe. More of that would be great to improve the player's confidence in moving forward. Adjusting the camera position down and/or adding a look down feature are other ways to improve.
I did like the big ghost and how it spawned the little ones. And the "You died" screen is actually pretty funny and works as a nod to both Super Mario Bros. and the Souls games : )