Cryptobirdies

Cryptobirdies is a game that was literally an April fool's joke, as going to rov.io/CryptoBirdies would link you to the song Never Gonna Give You Up by Rick Astley, thus being a Rick Roll

Gameplay
It would have you take care of hatchlings, and earn them, like in Angry Birds Match, but they would hatch from an egg and then would be bought with a huge amount of money.