Easier isn’t always better.
Too easy is boring. Too difficult is anxiety-inducing.
Just right is flow. Flow makes happy, engaged users.
Tic Tac Toe is a very simple, fun game for young kids. Then at some point they realise the ‘trick’ and the game almost instantly becomes boring. They can no longer find flow.
On the other hand, as they grow older and throughout adulthood, Chess is a game that doesn’t get boring.
The rules are much more complex. There are 288 billion possible move combinations after just 4 turns.
When playing against a partner at a similar level, each game feels new and just challenging enough to produce flow.