Gaming

• Super Mario 3D World
• TMNT: Shredder’s Revenge
• Shovel Knight
• Captain Toad: Treasure Tracker
• Minecraft
• Rayman Legends
• Pokemon: Let’s Go Pikachu/Eevee
• Lego Star Wars
• Kirby and the Forgotten Land

All have local co-op and would be solid choices!

Ultimate Chicken Horse is easy and bloody fun. You have to get from point a to point b with your character multiple times and each time you either die or make it. Each turn you also place an obstacle each. Really fun. It's a favourite in our household. Edit: sorry I didn't read your whole post. While it is competitive it's still fun... And different.

Stardew Valley!! The local co-op on the switch is my favorite way to play with my son. The game is so relaxing and once you get into it a bit it’s fun to see all of the ways we can divide up the chores and work together to make the farm better.

Good Job was a lot of fun. I played it with my daughter when she was about that age.

There's a game on NES that I highly recommend called Trog.

I believe it's actually an arcade game but you can still play 2 player on NES.

You play as dinosaurs collecting eggs ala packman while avoiding cavemen. There's a power up bonus that turns you into a T-Rex so you can smash them.

It's a ton of fun.

Yoshi's crafted world has a fun duo option that my daughter likes to help with.

Unrailed is a cute, arcade-like, cooperative railroad track-builder.

Death Road to Canada is a hilarious parody of Oregon Trail set in the thick of a modern-day zombie apocalypse, and would help with his vocabulary-building. It's clean and has no profanity (and the zombies have black blood).

Overcooked 2 is a blast, but it can be really difficult too.

I'm gonna vote for the Kirby's Return to Dreamland remake. It's playable in single player, but it was built with one-screen co-op in mind.

Untitled Goose Game actually has co-op in it. It's not a super long game, but it is a fun game. I played through the whole game with my daughter and she loved it. You can cause a lot of funny interactions throughout the game.

Sonic Mania has co-op! either you can take the lead as Sonic with your son as Tails, or vise versa! it's a great game, and a great introduction to the Sonic series

Any of the Kirby games have co-op and most if not all of them have demos on the e-shop so you can try them out.

Cat quest 2 is a simple game that also has a demo you can try cauae i'm not sure if i'll be too simple.

Moving out also has a demo to try and it has accessibility options to turn off stuff you don't like about the game.