It takes two is amazing, but AFAIK only allows for two players.

Casual Games

• Untitled Goose Game: silly, funny, and easy for anyone to pick up
• Overcooked Series: work together in a kitchen, may test your friendships haha
• Human Fall Flat: frustrating but funny platformer
• Any Lego Game: great to play with kids
• Minecraft: the most popular game for a reason
• Minecraft Dungeons: fun rpg based on Minecraft
• Terraria: 2D Minecraft but with easier crafting and more to do
• Pico Park: puzzle platformer, good for large groups

More Difficult Games

• Stardew Valley: adventure farming simulator (not very difficult but more involved than casual games)
• Portal 2: FPS puzzle game
• Cuphead: very difficult side scrolling shooter
• Borderlands series: FPS looter shooter
• Castle Crashers: side scrolling hack and slash rpg
• Left 4 Dead (1+2): FPS zombie shooter, playing with mods is hilarious

Non-Cooperative Couch Games

• Jackbox series: assorted party games, good for lots of people
• Super Bunny Man: silly fighting game with wonky physics
• Fall Guys: battle royal platformer
• Lego Party: looks like the Lego version of Mario Party though I’ve not played it

Overcooked 1 and 2

Cooking game they even most inept video gamers can enjoy.

If they are good enough, try Plate Up for a more difficult similar game.

Magicka and Magicka 2 are magic casting games that are absolutely hilarious and will have you freezing, soaking, burning, crushing and electrocuting your team mates all as you frantically try to combat enemies.

• Ibb & Obb
• DYO
• Wild Woods
• unrailed 2
• Lovers in a dangerous spacetime
• picopark

My boys and I played DuckGame an entire 3day weekend once. I set up 2 TVs so we could team up in Fortnite with a PS4 and a Switch, but honestly we played DuckGame more. I spent this summer with my 16yo playing Divinity Original Sin 2 coop split screen. It was fun until Act 3. Can’t recommend it, but ymmv.

Oh, when my kids were little we put a lot of time in Amazing Frog. And Minecraft, obv.

The absolute top 3 I can think of right now:

• Broforce
• Heave Ho
• Hidden in Plain Sight (not co-op, but it’s hilarious to play with others and doesn’t take much skill so it doesn’t feel unbalanced if some of the players have played it for much longer than others)

All 3 are 2D, funny, and great fun to play in a group.

Terraria. Seriously. Do a blind play through without a wiki. Super duper fun. It can be short or hundreds of hours, depending on your style. Great for groups as well, as it requires a surprising amount of team work.

Good party games:

• Ultimate Chicken Horse
• Gang Beasts
• Unspottable

More intense coop:

• Gauntlet
• Cuphead
• Spelunky

I’ve heard good things about DuneCrawl, but I’ve never played it.

If you are looking for a horror movie type experience, Until Dawn and The Quarry are great. You pass the controller when the character changes, but they’re designed to be enjoyed by a group.

Overcooked 1 and 2

• Absolum
• Brotato
• Crawl
• Ember Knights
• For the King 1&2
• Lovers in a dangerous spacetime
• Rotwood
• Dome keeper
• Heavenly Bodies
• Sea of stars
• TMNT: Splintered fate

These are all I could recall for now and since I don’t know what type of games you prefer specifically I just dumped a list of the games that I enjoyed playing with my GF and friends recently. Hope it helps!

The Trine games are pretty fun with multiple players if I remember correctly

Heavenly Bodies.

Another vote for Lovers in a Dangerous Spacetime.

If you like electronic dance music, Just Shapes and Beats.

If you liked Eye of the Beholder and wish there were a co-op Minecraft-visuals version, it’s Barony.

Boomerang Fu