[prg318]

Firefox is blocking the external javascript because the site is being served over https but the scripts are not. You can see this in the console:

Blocked loading mixed active content "http://examples.phaser.io/embed.php?f=arcade+physics/angle+b... [1]

HTML5 is less to blame here; the administrator of phaser.io should configure their service to serve these javascript files over HTTPS

[1] https://developer.mozilla.org/en-US/docs/Security/MixedConte...