Speaking of Castlevania tomorrow on Epic the Castlevania Anniversary Collection will become free for a week to claim. I think it includes all NES games!

As for the topic there is one game that I go back to for the past 5-6 years every time when I am bored and I need to just "wake up" - to think about something. It is The Witness. I tnink I have replayed the game 5 ot 6 times now.. The nature of game allows you to replay it many many times because you just cannot remember all the puzzles and their solutions - they are just too many. And the puzzles are just so good!

I think my comfort games would probably be Skate 3 and the Tony Hawk games, primarily. They are just fun to pick up and skate around and mindlessly enjoy.

Also, Dark Souls 2 SOTFS. That may sound strange to some, but it is my son's favorite game and he has had me playing it for about 8 years now, so needless to say I can kind of mindlessly run through that one too. Hated it at first, but seeing as he liked it so much, I pushed through and beat it. Now it's just something he and I go back to from time to time without much effort.

maybe try ISLANDERS, it's on GOG. I've played it for only a while but refunded not because i didn't like it but because Metro 2033 was at a sale for the same price and i though that's a better deal. Can't say much about the music, since i dont remember it :P. Im sure it's nice though, most music is in these types of games.

Something of a meta-example.

Any dice game within Witcher 1.
Pazaak/Blackjack within Star Wars.

For some reason such ''games within game'' tend to be relaxing, don't require much thought, but you can play them endlessly. (Being based on luck might have something to do with it.)

Been playing Dredge lately and found thats a game for comfort and destressing for me as a whole

Another one came to mind, that I do on console: The "Warriors" games from Koei. Load one up and murder thousands in almost mindless button-mashing.