I'm a solo developer and recently released Piskvor Prime, a five-in-a-row game for iOS. This started as a side project to experiment with a simple board game AI that I ended up wrapping into a complete game.
Your opponent is a glitchy robot that reacts to your moves — taunting, hesitating, and reveals bits of internal lore as you play. It is not unbeatable, but it has a bit of personality based on lots of text generated with LLMs.