I had a lot of fun learning physics with this project, and I totally understand your frustration over non-linear movement which is not very intuitive compared to how it is implemented in other platformers. While that kind of motion is quite tricky to get used to, it allows the character to be as precise as the player can make it to be, giving a much steeper learning curve with quite a reward (but only if you are into such things).
Thanks for giving your thoughts on improvements! This is a valuable feedback that will help me to grow.