Credits are a special currency that can help you do lots of things in the game! You can use credits to open up new countries, create new routes, buy new planes, upgrade your airports and planes, and more. Credits are a premium currency, which means they’re really valuable! You can also use credits to unlock special premium features that you can’t buy with regular cash.
If you want to use QuickConnect, which is a super easy way to connect airports without having to draw lines on a map, you’ll need to have some credits. Each QuickConnect connection costs 2 credits. And if you want to become the mayor of a particular city (airport), you’ll also need to use credits.