really liking it! I checked it out because I'm starting with Python and Pygame, and programming in general. A bit of constructive criticism (from an audio guy): the footstep sounds are really low and rumbly. It looks like you combined the low, rumbly "ambience" file with your "grass" footsteps. you could try using a different sample or put a high pass filter on it and your ambient sounds (100 Hz or greater).
I found that you can exploit the controls and hold both left and right to wall jump
Also turn up or replace the music! It sounds like environment noise. Nice job, hope to learn a lot from your project