How can I earn my Cookies' Affection?

How do I unlock new Cookie relationships?

Wait, how can a Cookie run?

How do I obtain new Cookies?

Can't I just buy Cookies directly?

How can I upgrade my Cookies?

Why should I upgrade my Cookies?

Can I reverse the upgrade of a Cookie?

I'd like to know more about Cookie rarity levels.

Where can I see a description of my Cookie's Skill?

What's a Cookie Relay?

What does the "Runs Left" number mean?

The game says that my Cookie is tired and can't run anymore? What can I do to help?