hey Hanni, thanks for the notice. did you by any means play on laptop and tried to jump with the up arrow? this seems to happen with certain kind of keyboards, but i'll try to get it fixed. did you try jumping with the SPACE key, or controller? because if that also doesnt work, we're in serious trouble ;-)

Hey thanks for your fast reply. I'm playing on a normal PC with a German keyboard layout and pressed Space to jump. Btw. jumping while running to the left works.

Edit: Yeah it works with a gamepad!

I have a similar problem where jumping while holding shift and right means only about half of space bar key strokes are accepted (or there is a significant delay?) so I am not able to complete the pond jumping puzzles in the very first part of the game... given up in frustration after ten minutes of failing at RNG decided puzzle... I am also playing on a laptop (Japanese keyboard layout). I feel like this game was designed with a gamepad intended and keyboard was retrofitted and barely tested - it is hella difficult (made harder by not using the default "WASD" movement keys...)