Nice job on this, I played to the 'good ending' and had fun. I especially loved the main character and his movement. I also liked that the final boss at first felt overwhelming, but on repeat plays allows for the player to develop a strategy for winning. The use of colors and light effects in the various worlds were also nice. Great work!
Like Thetra00, after I initially sold relics and had money, I couldn't figure out how to buy anything from the shop. I think the issue is that up to that point, no mouse is needed in the game -- including for selling items -- so it didn't occur to me to use it. (I quit out of the game and saw your comment here).
At the end of the game I tried selling The Good Ending in the shop (look, helping mayors doesn't pay my mustache wax bills), and I think I got a lot for it? Something I had was worth a pretty penny...