The chef looks great! I'm just a coder and not an animator, but the linear movement in the chef's hat is pretty obvious. Have you tried using the graph to make the hat move up quickly, slow down, move down slowly, then faster? This will make it feel like more like it is affected by gravity. Same with the chef's jump. (edit: actually it looks better in the editor on youtube than it does as a gif, so maybe you already do this) Also maybe you could use some squash/stretch on the chef's body.
