Nice! Good to see you make something for Pixel Day and it's even better when it's animated!
My constructive critique is that the body anatomy kinda looks a bit awkward especially the characters right arm. The main body is kind of big compared to it's legs. There are lack of shadows on this character without a proper light source. I suggest that you learn some basic anatomy and adding shadows depending what light source it spawned.
At least you put some effort on this and the end result was awesome thanks to being a gif art. Hope my suggestion helps and happy belated Pixel Day to you too. :)