in www/src/utils/particles.ts [407:418]
function addParticle(num) {
let i, p;
for (i = 0; i < num; i++) {
p = new Particle(
Math.floor(Math.random() * screenWidth - PARTICLE_RADIUS * 2) + 1 + PARTICLE_RADIUS,
Math.floor(Math.random() * screenHeight - PARTICLE_RADIUS * 2) + 1 + PARTICLE_RADIUS,
PARTICLE_RADIUS,
);
p.addSpeed(Vector.random());
particles.push(p);
}
}