The bundle itself is a mix of pen and paper RPG games + video games + other digital assets. I didn't look at all the video games, but the ones I did check out look like direct downloads from itch.io (not a code you'd use with Steam). I think that's fairly standard for itch.io video games too. Like for instance Baba Y Yo is a Steam game too, but they also sell on itch.io for people who don't have/like Steam.