Thanks to @sWaMPqUeeN and @MisterPookie I started playing Stardew Valley on Thursday and somehow logged 14 hours to the game since then. Not only does time seem to fly by while playing that game, but it takes very little effort. Some games (DS3, OW) I can't play more than an hour or two at a time because I get tired, perhaps from all the adrenaline.
What games have a similar effect on you, so I know what to avoid for the sake of my productivity?