Coronium Ace - Serializaiton ideas?

So as far as I can tell, the Coronium Ace games are instances that terminate once every player leaves, correct? Assuming that’s true, I’m trying to come up with ideas for when a player leaves, just serializing the game data itself to the local device, and then down the road, I’d be able to re-upload all the game data to the server side and pick up where I left off. 

Does that sound like I’m on the right track? Nothing super complicated, just player x and y locations, maybe some incidental data, etc. 

Curious how I’d pick up where I’d left off turn-wise too, gameCtx:setTurn( player_num ) perhaps?

Appreciate any pointers!

Mario