- Make the code better.
- If you do it worse, you are out.
- Better is intuitive - i.e. faster, smaller, more efficient, more robust/stable, more functional.
- Keep it simple.
- Functionality should be limited to its core aim.
- If the project should grow in undefined direction, fork it and make a separate one.
The aim is, that by making the code better, you/we make the world better. Still, in case if doing the code better, we will make the world worse... (unprobable, but not impossible) we need to think about it :D