Also, with the wall collider mishap, this is because I made a few of the wall colliders too short, so the player is hitting the ground collider behind them. I'm in the process of fixing this now, but I need to go through every ground chunk in the game to move the collider slightly out, so it may take a couple updates, since not all of the wall colliders are even placed yet. After the 10th or so screen only wall colliders on ground chunks that are necessary to complete the "true" path, or the path I think is the most obvious for beginners, are placed. I'll add this as a bug to the page. To avoid this for now, just try and press the arrow key pointing towards the wall of any ground chunks. I'll let you know when this issue has been fully resolved.
I'm glad you liked the level design!