1. No bugs, glitches, or crashing.
2. Good art direction and color theory.
3. Tight, responsive controls. Even Out of this World, Flashback, and Oddworld's grid-based movement was responsive.
4. Decent graphics or better.
5. Good sound effects and music.
6. Appropriate pacing.
7. A decent story or better.
8. Both physical and digital releases. (Yes, I'm including cart and CD.)
9. Addicting gameplay and just plain fun.