Game Center showing 'Not Ranked'

i recently made a Game Center account and got the apps cookie collected 2 and Crosby road. I hen played a bit and went to check on Game Center. What I saw was the to apps were under "Games" but it only showed their icons, and to the left said "not ranked". I clicked on cookie collector two and under 'cookie sheets collected' it said not ranked and I did collect cookie sheets. Crossy road also isn't displaying my high score on Game Center. What's going on?