JumpLab: a testbed for studying jump motion and scrolling algorithms of videogames

Jump speed sustain level

When the jump button is released, the vertical velocity of the jumper is multiplied with this value. Low sustain level allows you to control the height and distance of the jump by how long you press the jump button. This value is set to near zero in games like Nintendo "Metroid" (1986) that require precise control of the jump height.