u/Electronic-Laugh-671

(screenshot is from ContentDB page)

It's a really cool game by JavaFXpert, that lets one learn about quantum computing circuits. (searching within Minetest I also found this fork. Not sure what was changed, but I chose to install that)

Just be warned though, with the version of Minetest that I was using (5.6 I believe?) the game crashed when trying to reach servers to execute quantum circuits. I simply solved this through going into All Settings and explicitly granting HTTP permissions to "q_command" (the mod that apparently connects to IBM servers, I found the name by typing in chat '/mods')