You'll improve
This was nice.
The end was timed perfectly. The art was.. cute..
Now for the bad stuff...
You have to play to your strengths and not let your shortcomings sabotage the movie. You don't know how to animate walking at this point, yet you had about six seconds of a... shall we say ... no.. let's be honest.. extremely bad excuse for walking. The character didn't glide, he shambled. You could have don a close-up and NOT shown the feet, or superimposed the flower and body getting closer.. but what you did almost ruined the animation.
The bit with the talking sun... pointless and detracting. IF you are going to throw comedy and randomness in, you have to work a bit harder. The sun was in the film from the beginning, and then you turned around and pointed out that it was not real... BY INTERACTING WITH IT... If you do something like that, you should either go all the way with it (have the sun leave the galaxy and freeze the earth) or bring the joke to a completion in SOME manner.
Keep learning, PLEASE keep creating.