Sometimes simply isn't a bad thing
When doing animation sometimes the less frames you incorporate the more aesthetically pleasing it becomes. Now I'm not saying that you should reduce you animation I'm just stating that you don't need a billion frames for something like like this. In all honesty it took me a few glances to notice that you used 4 frames, yet you used those 4 frames very well. Keep up the good work, everyone has to start somewhere. As for "critiquing" you animation, I don't animate so I can't give any other helpful advice
newgrounds.com — Your #1 online entertainment & artist community! All your base are belong to us.