My partner and I recently revisited Sonic Adventure 2, and it wasn't because we have a special fondness for sending hedgehogs rocketing to their deaths at unpredictable angles or fumbling with Tails's Metal Gear. We were there for the Chao Garden—the side mode where Sonic and co. act as surrogate parents for little blorbo creatures who you can force to fight in karate matches before they've learned to walk. It's a feature so beloved that its failure to appear as a standalone game is a continued and baffling mystery.