Of to a good start there, but personally I would adjust a few things.
-The very start feels like it lacks inertia and a little more weight. The character looks burly, but doesnŽt feel like it, atleast not enough to really sell it.
-IŽd adjust the jump to a forward/downwards drop, like heŽs using built up inertia to slope the fall, and not jump up as he gets off the box. When jumping downwards, we generally try to make the fall easier and shorter, and not add to it by jumping upwards first unless its to jump over something.
- The landing could use more weight, like having him contract more as he hits the ground, take a slight mis-step, put and hand down to balance the fall and then use the inertia from the jump to get back up and moving again. Think of it like a soft ball, or a waterbaloon landing, squishing from the weight of the landing and then expanding again as it bounces off the ground.
Atleast those are the points IŽd work on.. Seasoned animators here probably have a much better take on it