Critique - Walk & Run

The walk:

Front view: your body is missing the left/right translation. So let's say during x10 (and of course for the other side as well), his weight needs to be over the screen right leg. Right now your body just goes up and down.
The head could also use some stabilizing, right now it swings with the body left/right. If you pick the middle part of the head, it should more or less stay in the middle with some overlap, but your head swings from left to right a lot.
The right arm more so than the left one hits a wall towards x32/x1. It does an outside swing, then comes in a bit until said frames and hits a wall for a few frames. Make sure that the arc continues throughout the loop.

Side view: the feet are sliding, it looks like they snap down and backwards, slow down, then accelerate before the lift off.
There is a hiccup in the spacing on his left arm, it seems to slow down around x10, then speeds up again.
The hands are too early in terms of drag and overlap. Look at x32, the arm just finished its backward swing yet the hand is already rotated back (delay that by 2 or 3 frames and I would actually lessen the rotation a bit).
His head could use a bit more nose up/down, when the body goes up the head drags a bit with its nose down and vice versa on the down.

The run:

seems good except one major thing: there is a giant snap during frames 1 to 2 and 15 to 16, as if he got hit by a giant hammer!!

:)