Click and a rocket bursts where you clicked; space is the finale. When nobody clicks, the show goes on by itself.
The explosions are not code. They are three .particles files that set each other off with children: the rocket's death sets off a burst, and every spark of the burst sets off a crackle as it dies, all of them with trails.
Each colour is a launcher's tint, and overrides.lifeScale decides how high a rocket climbs: it flies with no gravity at a fixed speed and life, so its scaled life is exactly its height.