I love this take on the theme, using scales for movement is pretty wild!
As for the gameplay, it is hard to predict how much weight is needed for a jump, but then again it's pretty funny to see yourself getting catapulted across the entire level ^^
One thing that would definitely help make it less frustrating if a jump ends in some spikes however would be if the scales did not get reset completely when you die. That way you could experiment a lot more and simply adjust a scale that is a bit off.
Anyways good job making your first game! And as it is the first game jam for me too, I will shamelessly suggest you give my game a try as well ;)