Can someone tell me a bit about the mini games?

[Vicks]

Originally Posted by Contemporary

Do you have to unlock it iwth a full popularity bar?

Yes! That's the only way to unlock mini-game levels. Once you do your 3 favors and finish the Adventure with Bloo, you can unlock any mini-game level. There are a few that are already unlocked from the start of the game, but filling the popularity bar gives you the chance to unlock the rest.
~Vicks