setInterval(() => {
    distSq = ast => {
        let dx = playerX - ast.x;
        let dy = playerY - ast.y;
        return dx * dx + dy * dy;
    };
    justPressed.Space = !justPressed.Space;
    let closest = asteroids.sort((a, b) => distSq(a) - distSq(b))[0];
    dist = closest ? distSq(closest) : 10000;
    keys.KeyW = !!closest && dist > 7500;
    keys.KeyS = dist <= 7500;
    if (closest) {
        playerAngle = -Math.PI / 2 - Math.atan2(playerX - closest.x, playerY - closest.y);
    }
}, 200);