Grab the face and pull. Let go and it boings back. Hold Shift when you release (or turn on Pin) to keep the stretch. Drag empty space to spin, scroll to zoom. Shaking him back and forth makes him dizzy. Keys 1 2 3 switch between hand, mallet and pin. Feelings mode makes the nub react; Damage mode lets him fall apart.
Drag him to stretch, tap to boop. Two fingers stretch two spots, or pinch empty space to zoom.
Hit, poke and over-stretch him to wear him down.