The Pivot part of you seems to show strongly in these animations.
That first animation of yours does have a cool concept, but I suggest that you work on...
[RepeatedLine] Anatomy. [/RepeatedLine] When his head shoots upwards, the proportions are very off. I do not practice the style of tween, so I can't give you much advice there. What I can say, however, is that your scene would look much better when animated Frame-By-Frame. Anatomy will boost the quality of everything in your artwork, from stills to animation.
Four or five layers? O.o It should take one.
The second animation consisted of...100% tweening?
Not much advice I can give on that one, except for the anatomic critique.
Look at people in real life. Google some bodily proportions. Etcetera.