Thank you for your comment and for trying out our game! The original plan was that you could still walk up the slopes, and eating cookies would increase your weight and slow you down, and ultimately unable to walk or jump past them. Due to technical difficulties, we were unable to figure out a solution to walk up the slope on time.
I will make more levels in a future update, despite the game jam having ended, and we will do our best to make more games that everyone can enjoy!