Belgian fantasy role-playing epic Divinity 2: The Dragon Knight Saga has a demo version! Just in time for you to turn your back on your family over the Winter holidays and club some goblins to death in the privacy of your game room/office/laptop parlour. The 2gb demo is the first valley of the game, which is a fairly hefty chunk of play, I think. And the game has, of course, been heavily overhauled since its original release last year, both adding new content and new visuals. And it was fairly pretty to start with, if a little grindy.
Also, in the full game, you can build an “abomination” to fight for you, which can’t be bad.