Theme: "Limited Space"
Game: "Harbor Tetris"
You are a crane operator in the harbor and you need to place containers on the ship to load it fully.
In this game I used mechanism where players are choosing themselves what kind of rules they want to apply:
https://ldjam.com/events/ludum-dare/54/harbor-tetris
Play it here:
https://wdebowicz.itch.io/harbor-tetris