From the group so far:
Ian MacDonald
Forbidden Island and Roll for Adventure spring to mind as non complex cooperative games.
Liz Christopher
Forbidden Sky is my fav of the Forbidden series. I mean it has a rocket that lights up and makes a rocket noise when you create a circuit. What’s not to love.
Cate Davis
Familiar Tales or Stuffed Fables, although they’re campaign games.
Chris Hobro
Flashpoint is a fun co-operative, also Castle Panic and Zombie 15
Kathryn Elizabeth Belton
Maybe something like King of Monster Island could be worth looking at (more expensive though) as you can play co-op and then eventually go back to competitive as they get better at managing having a winner/loser amongst them but with a game they’re more familiar with at that point? Or you could forever play co-op too haha
Katie Louise
Menara is a co-op dexterity game that’s really fun
Emma Carol
Back to the Future: Dice Through Time, Roll for Adventure, Beacon Patrol