Many many thanks to all the comments and suggestions!

So far, she looked at youtube videos of CK2, The Talos Principle, Minecraft, Stardew Valley, The Long Dark, Portal 2, RimWorld, Railway Empire, Cities: Skylines, SpaceChem, Opus Magnum.

The Talos Principle, Stardew Valley and The Long Dark are at the top of the list. But she is not through with the other games. (Of cause this is only by watching youtube reviews and lets plays, not playing herself.)
I have to say, its not as easy then I thought finding the right videos and there have to be in German.

My first thought was Mincraft. But by watching a video she got dizzy.

About the 3D game condition, this was just because of this video [https://youtu.be/Ellig1JgVPM] (in German).

The APU is an Intel Pentium G4560 as far as I remember, has a HD 610? GPU. The PC has 8GB RAM and a SSD with linux Mint 19 I think. This might be good enough for Stardew Valley but the other games I don't think that will be a good gaming experience. Which is kind of important because a slow PC can take all the fun out of a game.
So I was thinking of buying a GTX1650. (Would like to go the AMD GPU way but the problems I have with my Vega56 are to bad, but that is an other topic.)

Thanks,
Dax

PS.
The only game she is playing for over 10 years now is Swing from Software 2000, running in dosbox:) [https://youtu.be/di8Dh-QjpxI]

Just to add, I am playing Talos and Long Dark on a weaker Intel GPU.

Last edited by tuxintuxedo on 25 February 2020 at 7:49 pm UTC

Why the 3D-only constraint?

Well, here's a few suggestions anyway:

Islanders
Shadowhand
Firewatch
Valley
Back To Bed
A Short Hike
Evergarden
Leaving Lyndow
Eastshade
Train Valley
The First Tree

Quoting: Dax TailorSo far, she looked at youtube videos of CK2, The Talos Principle, Minecraft, Stardew Valley, The Long Dark, Portal 2, RimWorld, Railway Empire, Cities: Skylines, SpaceChem, Opus Magnum.

...

The APU is an Intel Pentium G4560 as far as I remember, has a HD 610? GPU. The PC has 8GB RAM and a SSD with linux Mint 19 I think. This might be good enough for Stardew Valley but the other games I don't think that will be a good gaming experience. Which is kind of important because a slow PC can take all the fun out of a game.

I think you are underestimating her PC by a lot. It should be more than capable of running those games with good performance. Opus Magnum and Spacechem are super light, Portal 2 is ancient; neither CK2 or RimWorld are too heavy. But my i5-3210 (5 years older and worse in nearly every aspect) can run The Talos Principle alright and even some Cities: Skylines if I am patient (it gets a bit slow in the midgame, but it's far from unplayable), so I'd say not to worry about it. Those games are nearly all over 4 years old and mostly from very undemanding genres. (Well, Cities: Skylines can scale up to whatever your computer can do, but if you don't go crazy with mods or gargantuan cities or settings it should be quite alright).

Thanks for the info about the Intel GPU/CPU. I have some games I can try next time I visit my mother. Like FEZ, Antichamber, Dust and IAWar. It's just to test the HW. This games are drm free. (I doubt she will play IAWar, but you never know.)