This is so obviously the creators of that game making fake transactions to establish fake value in their product. It's not hard to send 100k to yourself for something that has no value to make people believe that it does.
I can assure you that we're as surprised as anyone at the speed that this thing has grown!
Okay...
Rumor is a lot of ICO's do something similar in that they buy their own coin's with another coin like bitcoin which then goes right back into your wallet so you can buy more with it creating the illusion of tons of demand when you are really just cycling the same money through.