Thank you for the kind and thoughtful feedback! We actually had a discussion about this exact thing. We originally used left shift, but in playtests that sometimes activated people's "sticky keys" function on Windows. So we opted for J, assuming that the player would use two hands, one to control the character and the other to split/rejoin the spirit. I agree the WASD controls feel much better than arrow keys with J. I've only really playtested it with the WASD actually. My favorite is with controller though.
For our post jam build, what button besides J would you recommend we use for spirit splitting to accommodate people playing on arrow keys? Thanks in advance! And thank you for playing!