Started playing Quake Enhanced. It's great playing it again after so many years, but every so often there's an immersion-breaking pop-up telling me how I've done some trivial thing or other. Of course I have - I'm playing the game!

Is there any way to turn the notifications off?

If you play the game without Galaxy running, you will get no notification.
If you still want to use Galaxy, you can select "Settings ---> Game features" (see the attached image) and either disable achievements or turn off the notifications by disabling the overlay.

Thanks for the suggestion, but I don't have Galaxy installed. The achievements must be built into the game itself.

Sorry, I didn't know this: I've never played the enhanced version.

I took a look online and found out a couple of settings that might solve your problem: in the display options (see attached image) try setting the "Center Message Time" and the "Corner Message Time" to zero.

That turns off text messages like "game saved" when you press F5, but not the big white banners that slide in for achievements.

You can't disable those messages at the moment. Hopefully a option to disable them will be patched into the game at some point.

Sorry for necro but if anyone comes across this topic like me, i too find it immersion-breaking and could not play this port because of it. But i found a way that works for me:

*go to your Quake folder in %USERPROFILE%\Saved Games\Nightdive Studios\Quake\
*open the "achievements" file in a hex editor of your choosing
*change every 00 value to 01

now you have unlocked all achievements and should not see any popups

Thanks for working it out and posting it here.

My computer does not recognise the filetype of 'achievements' (I am using Linux)
So, when I use a HEX editor to change it, it changes the filetype to TGA image.

The game does not recognise this file, so it recreates the old one. And I am back to square one.

I have tried different HEX editors, but the result is the same.
Is there a way to save it as the correct filetype on Linux?

Don't use linux but you can try my file: https://filebin.net/q60w9kg7ypo4d4ln

For some reason, my achievements get reset eveytime I exit and relaunch the game. So your file doesn't work either. And not even manually unlocking the achievements. Why the hell is this happening? It's driving me crazy.
The notifications happen eveytime I relaunch and play the game, for the same things. It's super annoying.
On Xbox Game Pass the notifications don't even pop up.
This is an Horrible release.
Gonna refund it.

Might I suggest playing Quake II Original and throwing it into a source port?

There's severals:

FTE QuakeWorld
Jake2
Quake 2
Quake II Rerelease
Yamagi Quake II
Found on various sourceforges & githubs.

Best of both worlds, upgraded textures, no achievement spam.

I have the same problem, achievements notifications are so obnoxious and no solution has worked for me yet

The hex edit trick only works when you are offline or if you block the exe from going online.

I'll take it.