Yes that what I was talking about when I said "also a few games are supported but don't currently work for whatever reason". The overlay isn't currently working even though it is marked as having overlay support. I plan to report this tonight and hopefully someone from GOG will see it first thing tomorrow on mantis.

My default sound for achievements is a tired groan.

Thanks. That would be greatly appreciated.

As long as it can be turned off. Now that I think about it I hope in the future I can turn of achievement notifications entirely. While sometimes its nice to look at the list of stuff done after playing; the pop up in the game while playing is usually a source of distraction, annoyance and at worst a general immersion killer; the thought of it playing a sound which might or might not overshadow something an NPC says on top of it is a bit revolting.

I don't understand the ins and outs of the archievement system in Galaxy but for the games I have which support archievements some of them show a notification and play a sound while playing the game and other games don't.

An update on this as to why it may not be happening with Fallout: New Vegas. I'm using mods and NVSE to load the game. Just like Steam, a lot of that stuff disabled achievements. That's unfortunate, but that's how it is. I wish GOG would have made it possible to use some of these mods and still get achievements.