Thanks for the feedback! We are already theorycrafting at least one more mechanic to make the light form feel more useful than it is right now, but you're right than we can make a lot with what we have and not get into mechanic hell where we make a lot of mechanics and introduce them all at once and don't know what to do with them.
I see a lot of crutique about the controls, one of the first things I'll be doing after the jam is changing the default controls to something more standardized (zxc like celeste?), as well as adding the ability to rebind controls in the options. My decision for using J and K was that I personally have been using these keys when playing platformers for years now, but it didn't occur to me that it might be uncomfortable to others when uploading.