There are a few games I’ve played that use the “Tetris-like” shapes (Cartographer, Silver and Gold) but they are different enough in theme and other mechanics that it doesn’t feel like they’re too similar. What is the theme of your game, or is it more abstract?
I guess this is a common thing in the creative landscape. A game released last year has the same backstory/origin as mine. It was released while I had just entered my WIP into a BBG contest. There is always something different and unique about each game though. Just make sure your project is time stamped to reveal when you actually started on it.