I like games here and there, but I don't have big blocks of time available to get into deep games, and I don't want to invest hours into learning how to play something complex. Here are some games I have been dipping into lately that are simple and fun and are not big commitments.
Monstrum - A great little horror game that is played from the first person perspective. You play a guy who is trapped in an abandoned cargo ship with a monster. There is only one monster, but you have no way to defend yourself against it. You can only run or hide. You have to escape from the ship, and there are several different ways to do that, but you have to gather up materials to make it happen, for example you will need things to fix and escape raft. It can be completed in an hour or so, but there is no saves, and death is permanent. It is replayable because the ship's interior changes every time you play it, so there is a different layout every game, and it can be very maze-like. Also the monster can change. You face one of three monsters, and each has different strengths. This game can be very tense.
Versus Squad - If you remember SmashTV for the arcades back in the 80s, this is its successor. This is a top-down arena shooter. It is almost mindless violence, but not quite completely mindless. If you want to live long, you need to employ strategy to defeat huge hordes of enemies. You can build barricades, but that only slows the enemies down a bit. It is just successive waves of enemies that grow more powerful each wave. If you are both very lucky and you play very well, the game can last up to an hour, but usually they last not much longer than a half hour. You will eventually get overrun, so this is not a game that you can beat, only a game that you try to get higher scores. It's great little game to blow off some steam with.
Plague Evolved - I hear this game is popular for mobile devices, but I only know about the desktop version. A fun strategy game. The objective is to design and evolve a disease that kills all of mankind. You win when every last person on earth is dead. A little bit of knowledge about epidemiology can help here, although it is a bit simple and arcadey for a strategy game. There are all kinds of disease scenarios you can choose from, from common viruses and bacterial epidemics, to wild and exotic diseases. A game lasts about 20 minutes, so it is bite-size fun. I like to turn off the in-game music and throw on some of my own music. It isn't hugely challenging, but you have to figure out how to spread each disease to overwhelm humanity before they figure out a cure.