First off: Thank you for your honesty, and taking your time to try the game.
Secondly: It is our first project in the GODOT engine and we do not have much experience in it but the stairs might be an engine problem. It works for nearly everybody except 3 people we know of.... And yes, we know the movement will need a rework...
thanks again for the feedback!
If you have any ideas for us to make the game better, please let us know on discord(https://discord.gg/wv4YSkR)