Does Portal really count as “non-violent”? You commit murder at least once.
But also one thing you can do is play the two player co-op mode on Portal 2, which as far as I know is pure puzzle solving.
The stories in Portal are great though, especially Portal 2 which is rich and funny. You could just skip the end of the game and I think that would be pretty non violent? I don’t know if destroying a machine counts as violent.
(I originally thought GP was making a Companion Cube joke, but now I’m not sure.)