Shipped this project!
I built a chess game in godot. Started by following a tutorial for the base game, then kept adding things on my own (as computer opponent with three difficulty levels using Minimax, an options menu with volume controls, proper scene navigation with a GameManager handling state between screens, and draw scene).
The hardest part was the game logic. There was a bug where the computer was wiping pieces off the board without actually moving to them, took me a while to figure out it was a board restoration issue inside the Minimax simulation. Once that was fixed it actually played like a real opponent.
Pretty happy with how it turned out.