Its just some exageration to make the movement more fluid and readable

I know this is nit picking but why are his legs longer in running animation and jumping across animation?

pew pew

Very nice!  Remains me my 'tiny contra force' animation, though yours is much more detalized and better animated. 

Lovely!

Pixeditor looks sweet (and it's for Linux, thankyou, thankyou, thankyou!)! Going to give it a try.

Very nicely done.