The previously mentioned mysterious disappearance of some tags seems to be solved. In some instances using JS string.replace for BB Replace() has caused mayhem. Now string.replaceAll() is used, which solved tons of initially weird issues.
Another pitfall are array indicies. If they are not full numbers, make sure to use Floor(index), js cannot use indicies like eg. 5.3, but requires 5.0, for example.
Also, this online version contains test1.png and test1.mp3, so you can test those. It's however a js restriction to mandate a user action prior playing a sound. For music etc. it is therefor advised to implement a startscreen mode, in which the user has to do a click or keyhit to start the game and the music.
In general you should make use of your browsers javascript error console, esp. if something is not working.