You get in early you can double your Bitcoins but as long as there's more people playing after you otherwise you might as well send your coins to a wrong address.
After playing this for a few months and completing all the missions I still get the urge to snipe helicopters and blow up the blood thirsty animals daily. The only complaint is the helicopter and the invisible walls that is disappointing but the physics are improved overall but would like to see limbs being shot off for the next one.