A nice start, you've got the key poses down. However, try to work on your timing and spacing- and be a bit more creative about morphing, it can be very fun. take a look at stuff like this(although i'm sure you've already seen it):
https://twitter.com/iemon9999/status/775005055107735553
here, the key frames are clearly defined, but it's the creative swooshes in between that really define it.
also- another tip- when making short stuff, make it a gif, and post it in the art section instead- stuff like this doesn't get too much love here. It'll also challenge you to make things loop seamlessly.