The thing that looks weird to me when I saw it is when the leash gets to its max. lenght and pushes the swinosaurus back. He just doesn't have enough impulse there to the thrown away that much, it feels more like he slows down and then something pushes him forward.. it would look better if it was speeding up and was going a LOT faster then the leash pushes him... there's also a little bit of feet sliding when he goes towards the camera, but that could be because he's sliding a little bit in the sand...
Other than that, really great work there...