It might help to know how you visualize the world. As in, is it event-driven, where things only happen if you move from place to place? Or time-based, where things happen periodically and commands are queued for the next tick? Is it 2D or 3D or completely fluid in how things connect to each other? What sorts of ways can items interact with each other, change over time, etc.?

Obviously, at a minimum you need:
1) Player profile management (stats)
2) Player inventory management
3) Table of game items
4) Bestiary
5) Zones

You have to define your game before you can even think about looking for tools to build it.