What makes the perfect game? over on kuro5hin.org. Summary:

1. It must be infinitely replayable
2. It must be “skill scalable”
3. It must be always fresh
4. Include a campaign, “freeplay” and “sandbox” modes.
5. Be able to move the game from a simplified mode to a complex mode.
6. Have an comprehensive, optional tutorial
7. Make it fun.
8. Include Single AND Multiplayer modes

What makes the perfect game? over on kuro5hin.org. Summary:

1. It must be infinitely replayable
2. It must be “skill scalable”
3. It must be always fresh
4. Include a campaign, “freeplay” and “sandbox” modes.
5. Be able to move the game from a simplified mode to a complex mode.
6. Have an comprehensive, optional tutorial
7. Make it fun.
8. Include Single AND Multiplayer modes