The movement itself feels good in my opinion. I think the layout of the controls is what I find frustrating. At least on a QWERTY keyboard, the K key is far away from any of the other keys, so it's hard to easily reach without having to move one of my hands, making it not very viable to press during gameplay.
I also think it would be cool if WSAD and space were usable for movement and jumping, since I usually use those for platformers. But I know that most people just play with arrow keys.