Deep Rock Galactic: If you're a fan of team based FPS games this is a must play. You're a dwarf working for a sketchy space mining corporation and your missions are to basically strip the planet of all of its valuable resources while fighting off hoards of giant bugs. It's multiplayer with up to 3 other people but you can also do missions solo just to get the feel of the game, although later missions and deep dives absolutely require a team since they're harder than coprolite.
Kingsway: A pseudo operating system with a rogue-lite medieval style point-and-click RPG. The goal is to stop the Sky Eater from destroying your world while battling monsters that come in the form of pop-up windows. There's 7 different endings and 9 different classes making for great replayability. My only complaint with this game is that it's not long enough, and I have over 100 hours in it.
Metal Hellsinger: Doom if Doom was a rhythm game. You play as a demon named The Unknown on a mission to get her voice back and you do this by stabbing, shooting, and exploding any demon that gets in your way, timing all of your shots to the beat of the music, which changes per level. It's a little hard to pick-up at first if you don't really play rhythm games but it feels great once you get the hang of it, especially when you get a good combo going and the music tracks start picking up. Troy Baker plays the part of a demon skull named Paz, who acts as the game's narrator as well as one of The Unknown's first weapons. Must play if you like heavy metal and exploding demons.
Yakuza: The series as a whole is great, but the games can be pretty long, especially if you're trying to complete everything. In short they're linear, story focused beat-em-up games with over the top fighting and finishers. I'd be here all day trying to explain the story, but the meat of it is that you're a guy named Kazuma Kiryu and you're trying to get out of the yakuza, but then a lot of bad stuff happens. It's as charming and funny as it is serious, if not more so, so don't be intimidated by the serious nature of the main story, the rest of the game is mostly lighthearted. Kiwami is technically the first in the series, but there's a prequel called Yakuza 0. You can start with either of those, just be sure to play one after the other. I'd honestly say just start with 0 for the full story.
That ought to do it for now. If those games don't keep you busy for a while then nothing will. These are typically the games I'd recommend to my friends that don't play very many video games.