Thank you for reporting the bug!
Probably linked to the 'down' button being pressed while landing after a jump. The character's movement gets disabled when you 'look up/down' and it doesn't get enabled back correctly.
had that too.
too bad that the game doest seem to save.
played until i got like 70 coins, so quite far.
then had the running issue, so I restartet the game.
on the screen there was new game, which i didnt want, so I ran to the right.
some guy had some dialog, I pressed some button and back I was with a new game.
still had attack and walljump but still back at the start with 0 coins :-/
Thank you for playing the demo man! 70 coins is a lot indeed, I'm sorry to read you got stuck too.
I'm currently rewriting the part of the state machine which causes the game to softlock when switching state. I'm going to release a new version of this alpha without a lot of these bugs. It's a work in progress ;)
No, unfortunately the saving system doesn't work (yet!). I'm currently learning how to build one properly!