Just a few observations:

1. It looks like the feet are stomping instead of stepping. The toes need to kick up a bit more during the step and then come into contact with the ground after the heels touch down.

2. The forward motion is a bit jumpy, i.e. there are times when the body surges forward and other moments when he stands still. The character motion should maintain consistent forward momentum and have a bit of up and down motion.

3. The arms snap to a stiff-arm position (locked elbows) and then bend back before the arms reach their full back-swing position. They should lock at the end of the swing instead of before it.

4. The speed of the animation is also a bit quick. You might consider slowing it down a bit so we can see the animation clearer.

Not bad, overall. Keep it up!