Cool platformer and a nice touch of puzzles. This is actually good for your first time. I like the story and beating the Evil Lactose Intolerant King is satisfying, him lying on the ground. I actually tried jumping over him 10 times where all you need to do is stomp on him, facepalm.
What bothers me is the scaling of the pixel characters, it destroys the pixel. The camera can be improved with smoothing. If you want to build up more on this platformer, you can watch Jonas Tyroller's platformer tips. Goodluck on your gamedev journey and more games to come!