Thanks for trying the demo!
Not sure what you mean with the "stays stuck in this position" part though, there are only two things I can think of:
Either you are crouching or you fell too high causing a hard landing, but the hard landing one does not line up with the next part of what you said "and walks".
So I have to guess you are crouching, there are several issues with the crouching animation in terms of it looking a bit weird, which I've been trying to slowly improve upon.
If this is not what you mean then I'm not sure what it is.
There is no newsletter at this moment and to be honest I'm not 100% sure how and/or the best way to set one up either.
So right now the best way to keep up with the game is either here or on twitter:https://twitter.com/ApapappaGames
Anyway, thanks for the feedback and glad you like the game! :)