Particles.js

現在JavaScriptでいろいろなプラグインを使って遊んでいるのですが、Particles.jsを使おうとすると

Uncaught TypeError: Cannot read property 'speed' of undefined

というエラーが出てしまいます。

HTML
1<div id="particles-js"></div>
2<script src="js/libs/particles.js"></script>
3<script>

JavaScript
1    particlesJS('particles-js', {
2        particles: {
3            color: '#fff',
4            color_random: false,
5            shape: 'circle', // "circle", "edge" or "triangle"
6            opacity: {
7                opacity: 1,
8                anim: {
9                    enable: true,
10                    speed: 1.5,
11                    opacity_min: 0,
12                    sync: false
13                }
14            },
15            size: 4,
16            size_random: true,
17            nb: 150,
18            line_linked: {
19                enable_auto: true,
20                distance: 100,
21                color: '#fff',
22                opacity: 1,
23                width: 1,
24                condensed_mode: {
25                    enable: false,
26                    rotateX: 600,
27                    rotateY: 600
28                }
29            },
30            anim: {
31                enable: true,
32                speed: 1
33            }
34        },
35        interactivity: {
36            enable: true,
37            mouse: {
38                distance: 300
39            },
40            detect_on: 'canvas', // "canvas" or "window"
41            mode: 'grab', // "grab" of false
42            line_linked: {
43                opacity: .5
44            },
45            events: {
46                onclick: {
47                    enable: true,
48                    mode: 'push', // "push" or "remove"
49                    nb: 4
50                },
51                onresize: {
52                    enable: true,
53                    mode: 'out', // "out" or "bounce"
54                    density_auto: false,
55                    density_area: 800 // nb_particles = particles.nb * (canvas width *  canvas height / 1000) / density_area
56                }
57            }
58        },
59        /* Retina Display Support */
60        retina_detect: true
61    });