Gameplay

Health, damage, dying and coming back; and what the world hears from the character.

Health	Tracks health that damage lowers.
Fall Damage	Hurts on long falls and kills on very long ones.
Crush Damage	Kills a character squeezed against the world.
Respawn	Brings the character back at the last checkpoint.
Footsteps	Reports each step and landing.
Contact Events	Tells the world what the character stands on and bumps into.
Physics Trigger Proxy	Lets Unity's own triggers notice the character.