I have not really been keeping up to date with all the changes... With a game of this type though, new players need to keep joining and buying the new cards they are creating.

They need to create some sort of battle mechanic with the land feature that allows you to create armies you can attack other players with. The more cards you have the bigger the army you can create to kill other players.

It is difficult, because the people who have lots of cards have to be rewarded for owning a lot of cards, but at the same time you want new players to join and still be able to compete...