My happy fun time game is Doki Doki Universe. It's a super cute game where you play as a robot who needs to learn about humanity, or get destroyed for being so out of date. The gameplay is simple, you travel from planet to planet and solve people's problems by summoning items for them. It has cute graphics and funny dialogue. It also has a segment where you take mini quizzes for points and then get analyzed by a lil cartoon therapist.
My other addiction is less cute. Don't Starve is a pretty literal game. The game drops you in a strange wilderness and simply tells you to not die. You have to collect food and build fires and run from monsters in an effort to last ad many days and nights as possible. If you die, it's pretty much game over. That game is like crack to me. I can sit there staring at it mindlessly, just collecting berries and building a reserve of dry grass and twigs for campfires. I'm not great at it, but it's a lot of fun.