Damn this game is so touching. The music, graphic story and simple game play all combine very well.
The puzzle is pretty good, i like the mechanic with possessing and moving through the level. But i think if you can use mouse to move the spirit, and hold click to possess the things and release to drop it can be a bit easier to move around. And with mouse you can add more environment puzzle like at the last place before the resurrection.
And if you use mouse to move spirit, you can add another complication with WASD to move maybe a companion so the puzzle will have more variety.
Also if you show the range between body and spirit like how far the spirit can go can be a good thing too. And last you can add ragdoll physic to the body so when you move it around it will bouncing left and right haha. Overall very nice game, I like it.