Richard Clark:

Great setup you have!

However, in general, it lacks the fundamentals

Your characters lack weight to them and are floaty throughout.

I would suggest learning the simple "bouncing ball" exercise to start understanding the basics of animation. As well as the "flour sack" exercise to understand the spine and hips/root movement.

Arms are popping in places...watch out for hyperextensions. I would recommend not working in IK arms if the characters don't need to touch or hold on to a surface.