I just recently bought another ITX Mobo, CPU and RAM, and the CPU is an i5-6600K and the Mobo is a gigabyte H170-ITX
I did a bit of playing about with Mint 19 Cinnamon for a laugh and I used the onboard Intel 530 rather than the 970 I was going to plonk into it, and well, blow me, but I quickly copied Dark Crusade onto it, from my main Linux PC and I added it to the steam list ( So it does not have to download it all ) and I had a play, and it was fine.
I then added the CameraZoom files ( cos who the hell can play that without them ? ) and played the games for a bit in 1920x1080 with all the details up and it handled the game fairly well.
It was not 100% perfect no, but as someone who despises the intel GFX, I thought its come a long way since I last tried it.
There is absolutely no way it comes close to a half decent ATI or nVidia, but it is able to play games if you lower the detail, and the resolution.
Depends of course on how much yo uare willing to lower them, and what game you want to play doesnt it?