Synch games between iphone and ipad

I have recently acquired a new ipad. I also have an iphone that is used to play various games such as sudoku, word games etc. Is it possible to synch the games so they are at the same levels?

I've checked on google which suggests simply signing in on the game centre but still the games are not synched across the devices.

I have the Iphone 7 & Ipad 7th Gen Wifi 10.2 inch.

Any tips?

Thanks :)

Kate