• Scratch cat is experimenting with gravity. • When the cat is on the earth (standing on the green grass), jumping (press space) is fairly hard work. • When the cat is on the moon (standing on the grey rock, where a space helmet is needed: press cursor keys to move left and right), it takes a lot longer for the cat to come back down after a jump. • If you want to experiment with changing the gravity manually, turn "Auto gravity on" to 0, and then change the gravityStrength slider.
Thanks to @ScratchyLift for help with ideas.