I love the walk, it looks really good. The only thing I would change are the hips as they go up after the step. It's good how they go up after the foot plant, but I would add more rotation and weight as the guy pushes himself up from x5 to 6, 7 and 8. Nothing huge, just a bit more, since he's pushing himself up and more weight is on the leg/hip.
The other thing could be because of the quicktime loop (how can you not have that extra double frame at the end of the movie?), but check your head and chest towards the of the cylce. Looking through the front view it rotates to the right, but during x1 and x2 it stops rotating and resumes on x3. This leads to a little stop and pop as you play it in real time.
You asked me to be picky, so there you go. ;)
Captain Underpants: The First Epic Movie Trailer -
6 hours ago