It is a fact that we have records of almost everything in Gems of War, including when the player started playing. I, for example, started on December 10, 2014, registered on Steam.
This suggestion is not for login time, type, “between all days to win certain prize”. It would be a birthday gift along with Gems of War. After all, many of us already have Gems of War as part of our daily lives and we often can not log in daily, losing out one day or another, but we are always present the way we can. That would also spur new players.
Of course the present could be a title (which would be displayed next to the player’s name on the status screen and visible to other players) as I already suggested. It would be cool to have the title of 1st, 2nd, 3rd and 4th anniversary in Gems of War.
But even better would be to win a creature. Not a creature that already exists in the game and comes in chests or portals, but a unique creature. She would not have to be an extremely powerful creature as well, for the most important thing would be to have her as a memento of our time with the Gems of War family.
Anyway, I still hope to be for many more years watching this beautiful game grow and grow, getting more and more fun.