So i want to make a 3d first person game, where you are admitted to a theme park and are allowed to ride many rides. I want it to look just like a real one would, and you could customize your character. I want players to have the best experience possible, and be online with other players. You should be able to earn money working at stores or selling tickets, and be able to buy stuff and extra tickets in case your friend needs one that day. You could buy tickets with different lengths, and a lifetime costs real money. I would have many roller coasters and other rides, as well as a water park and everything else.You could see other players, as well as people. They would spawn in different parts, and realistic physics would apply when they are hit. You could fight, and be escorted out by cops and made to wait or buy another ticket. It would be a 24 hour daylight out. Sounds and graphics would be as real as possible. Do you think this is achievable with java and would people play this? Would they pay for it? What engine would be best for this?