You’ve got everything infinite (materials, health, weapons). Can be played both as single-player and multiplayer.
In this mode the players get to know each other and maybe build teams. The goal for this mode can be that people get as many friends as they can.
Single-player or multiplayer. You have to protect yourself from monsters, build house/fortress, make weapons.
There maybe a team survival mode as well.
Mostly single-player, but may be played cooperative. The goal of this mode maybe to solve as many riddles as possible. The game starts with simple tasks and becomes more and more difficult. Some form for artificial intelligence will track progress.
How is the idea?