Gaming

I recommend

• Pico Park

• • a co-op action puzzle game

• Ultimate Chicken Horse

• • a party platformer game where you build the level as you play, placing traps and hazards to screw your friends over, but trying not to screw yourself.

• the jackbox games

• • Jackbox Games is the party game-making studio best known for hit games like YOU DON’T KNOW JACK, Quiplash, Fibbage, Drawful, Trivia Murder Party, and more! Think of us as the child of classic social games like ‘charades’… the child who dropped out of college, then earned the family’s respect by founding a jam company.

These aren't exactly short, but are great in co-op and can mostly be played with no hurry at all

Satisfactory

Civilization games

Barotrauma

Borderlands series

Phasmophobia

Battlefield 4

Left 4 Dead 2

Rocket League

Golf it! (IMO better than Golf with your friends)

Payday 2

Worms Armageddon

Magicka

Trailmakers

@martinjuhasz

• You Suck at Parking
• Minecraft: Dungeons
• Minecraft: Legends
• PSO2: New Genesis

Hammerwatch is a fun pixely co-op roguelite hack'n'slash. Up to 4 players.

20XX is a cool mega-man like roguelite too, but the co-op is two players only.

Mindustry is a kind of base-building/tower-defense mix and it surely is an unusual co-op experience. We loved it. Up to 16 players!

Grounded for sure. Seems like it might be perfect for what you're looking for.

Starbound, Terraria and Planet Centauri follow the vein of Minecraft.

All Neo Geo games from the Metal Slug franchise can be finished in one sitting in any of their PC releases (Amazon Prime, GOG, Steam, etc.).

All 3 River City Girls games have pretty generous saving systems.

The Ultimate Ninja and Ultimate Ninja Storm games from the Naruto franchise, while technically being competitive games in multiplayer, all have overall pretty quick matches. Dissidia 012 Final Fantasy, Dragon Ball: Budokai Tenkaichi 2, Knight Club, Knight Club+ and One Strike also share this aspect.

Micro Mages, although potentially pretty long due to its arcade nature, can be played in short sessions due to being sold as a NES ROM, which lets players run it on emulators with save state features.

ENDLESS Space 2 might be interesting too, since it's turn-based and it automatically saves every turn, as well as having manual saves.

My favorite game to play with my friend who has a kid is rounds. 1v1 2d “shooter” where you get a power up every time you die. First to die 5 times looses. Short games, easy to pause in the middle, and scratches that competitive itch. Probably like $2 on steam

@martinjuhasz There are a lot of single player games that I could suggest, but the best one in my list is Getting Over It with Bennett Foddy

Maybe try minetest it is FOSS, potato friendly (it runs on phones) and you can make your own server. It is something like Minecraft if Minecraft was playable only with mods. So it is voxel engine you get mods on. There are games and mods accessible through launcher.