Slither Deep was my third game. It took about two weeks to make, and contained everything I had learned about Godot to that point. I was fascinated with the achitecture of Minesweeper games, at the time, and this combined Minesweeper with the Roguelike genre.
It's fully functional on mobile devices, and submitted to Apple and Android stores. I'm pretty sure it's missing from one (or both) since it hasn't been updated in a few years. Still, I had fun making it. I think it's the first time I procedurally generated the levels for a game.