A game with:
-A unbreakable physics system
-Beyond perfect optimization
-Extensive procedural destruction system, be it cutting a blade of grass in a hundred pieces or a nuclear bomb simulating the destruction by generating it, not a scripted event
-Procedural map creation which creates a map either quarter or half the size of earth, the procedural generation seamless by making every location look hand crafted by any means
-Generated variable sound effects
-Have all chemical reactions realistically connect to the world surrounding.
-Powerful liquid system and particle system which allows you to even create sand sculptures by just dropping sand.
-In-game gamemode editor which allows users to configure each aspect of the game's generation and rules, also establishing events, starting positions etc., allowing for people to easily create events like racing, deathmatches or survival out of thin air
-Ability to interact with any item in the game, no matter what it is. Be it picking up a pen and writing with it, throwing it or using it ammunition for a crossbow, or grabbing a mechanical item and dissemble it up to the bolts and screws
-Perfect human AI allowing conversations with text-to-speech, a improved version of CleverBot in which humans each have their own personality and can react to situations based on what the user says
-Default sandbox gamemode in which if you write things in, the game generates the models randomly with color, width etc., unless the user inputs additional arguments (i.e. typing in 'wrench' and spawning 100 will spawn 100 diffferent, random wrenches; typing in 'wrech, black, shiny, speaking' will spawn wrenches that are black, shiny and can speak, but the other arguments will still be randomized)
-Complete ragdolled player in every situation, allowing for better parkour elements, flips, and also tripping over or slamming one's self of a wall or by obstacles
-Scenario spawning system which allows you to type a scenario (i.e. 'bank robbery', 'alien invasion', 'nuclear strike', 'zombie invasion', 'world racing tournament', 'fishing') which will randomly generate a scenario based on those situations, allowing the player to review and change the settings before spawning/creating it, similar to spawning items
-Fish AI