IDK if released as a “cloud edition” or native, but https://www.nintendo.de/Spiele/Nintendo-Switch-Spiele/It-Takes-Two-2265759.html is probably the best co-op game we ever played with my wife. We played streaming from PC, IDK how good Switch port is.
Other than that, some of our favourites (tried to sort by relevancy to your question):
- Children of Morta
- Overcooked 2
- Guns, Gore & Cannoli 2
- River City Girls
- Death Squared (not PvE, puzzle game but a great one)
- Snipperclips (ditto)
- Super Mario Bros U Deluxe
- Luigi’s Mansion 3
- Pico Park (better with 4 players)
- Unrailed (maybe not very casual/easy though)
Other games that may not be your cup of tea but still:
- Mario Party games
- Warioware Get it Together
- Crawl
- TMNT: Shredder’s Revenge
- Super One More Jump
- Out of Space
- Enter the Gungeon
- Marvel Ultimate Alliance 3
- Urban Flow
- Catherine Full Body (has a co-op mode)
Hahaha didn’t know this exists, Thanks I will!