Your art is really cool! Did you create everything? In terms of control, I had some difficulties with the wall jump as it isn't intuitive. I also ran into a really interesting bug where I possessed the small jumping larva and got stuck inside the collider because I jumped close to the collider at the same time I unpossessed the larva. 
Viewing post in Possession jam comments
No, the art is made by o_lobster.
I'm a programmer. I made the character movement system based on transform.translate and my own custom velocity handling.
The wall jump now is created so that you must press against the wall. Also, I understand the players wanted to turn against the direction they want to jump. I must rethink the wall jump.
I'm currently working on a bug fix for wall slide and will upload it shortly.
That's a cool bug you found there, also I'm glad you uploaded an image. I'll add the bug to the fix list :)
Thank you very much for your feedback Goblin, I genuinely appreciate it :)