Once you get to meet people through the game or friends and family you could invite them to come and play in your game. You could race each other in separate side games or during regular play with side conversations, emoji, or memes
If you get really stuck on a level you should be able to get some help. Maybe you could add a help button after 10-15 losses that would give you a hint on how you can defeat the level your stuck on.
It would be nice to get to text teammates and ask for help or pointers on the game. You could be able to make friends around the world, but you would also need a way to block a person if they were not being respectful