Ty!

Hi, I started to fool around with pixel art not so long ago just when I discovered how to import my own assets into the Unity and make use out of it. As a starting point I have chosen "Piskel", free editor on a browser, to do all the work on and so far I feel pretty comfortable with it.
I am trying to make 2D animations as well as just single frame images. However as newbie I have to learn a lot here. I haven't done too much yet however I feel like some feedback on my current work could give me a ton of information and help with seeing how pixel art should look.
Below are my first arts, could you please tell me how could I improve them or what should I avoid in the future creations. Also, that's probably too vague, but I really struggle with walking animations (as you can see from sprites below), could you give some tips on how to position legs and whole body so that it doesn't look as "retarded" as in my animation?


Same model, but with some environment:





Thank you for your time and sorry if my English poked your eye to hard.