Thanks, glad that you like the art! :) The way wall run works is you just press space when you're right next to a wall...but you kinda have to be high enough so that your feet are still in the wall area (you know, to be able to run on it, after all :P ).
Thanks for the feedback! Several people already reported wall running to be a bit too hard or just not how they expect it to work. We'll look into it post-jam. :)