Welcome to Pixelation, I hope you enjoy your stay!
Now, I'm not much of an artist myself, but from what I can see, I'd say that the animation (to me) is a bit too rough and jumpy. Maybe add in a few filler frames here and there.
Apart from that, its all good in my eyes. Maybe a bit of a shading issue on the shirt, but you should probably wait for someone else's opinion on that first.
My two cents,
Good luck