Hi,
The sound functionality was implemented using a Flash plugin. This was in
2008, well before HTML5 audio came along (around 2011-2014).
Flash has since then been deprecated, and it's not running at all on most
web browsers. Which is great: Flash had an awful lot of security issues.
The (relatively minor) downside is that it broke audio playback in a few
places.
I'll need to work a bit and reimplement the sound effects using HTML5
audio. It'll be much nicer overall than the flash thing. More lightweight,
standards-compliant and all that.
- Hessu