I live the idea but the screen clutter is a bit too much. Finding a better cadence of when the various ghost text pops up I think would help a lot. It would also be nice to have some way to identify which spirits were in your party and which were not. I had to shuffle around a bit to try and identify the right spirit at one point. I would have also liked it for the action buttons to be in the in game spirit info screen.
The basic idea with different spirits giving different abilities could be expanded out quite nicely I think. I also liked the music and art.