Fancy beautiful No-Mans-Sky-without-the-orange-water type rpg with a pinch of chiptune and pixelated guis. Exploring an entire planet and fighting enemies from giant worms to an alien mothership, or relaxing in saloons and walking through abandoned cities, thriving villages, grassy plains, etc.
It would have to have a huge variety of environments and locations. Cities, suburbs, forests, snow etc.
Giant amounts of player customization, party member upgrades, large story, NO CRAFTING SYSTEM, free dlc, crossplatform multiplayer with optional pvp.
Creativity placed into the weapons provided from the game and a vehicle/town creation system like in Spore and weapon creation from Dead Rising.
Basically, the ultimate sandbox rpg.