Super Mario Maker is a blockbuster hit for the Wii U home gaming console, according to Nintendo. And maybe that is because the create-your-own Mario game is so powerful that you can even build a computer inside of it.

Mario Maker player Trousers designed a level called “Run a Tiny Computer!” using the popular Nintendo game, and it really works. It’s simple, and it can only add the numbers 0+0, 0+1, or 1+1. But what else do you expect from a calculator that runs on Mario enemies?

Nintendo reported early this morning that it missed its earnings expectations for its fiscal third quarter, but it also noted that it saw a strong reception for Super Mario Maker. It has surpassed 3.3 million copies sold. The publisher said that it wants to keep focusing on the game going ahead because it thinks that more people will want to see the kinds of stages that people like Trousers can come up with. That could translate into more hardware and software sales, but it could also lead to more people potentially spending money on downloadable content if Nintendo decides to make an expansion for Mario Maker.

We took a look at this computer level, and we found some complex computer science. Put simply, the level creator used Bob-ombs (the walking bombs from Mario games), coins, and P switches (which turn bricks into coins and coins into bricks) to create gates that turn on and off to perform calculations. That way, when you try to add together 1 and 1, the level can process that information through these gates to give you an answer.

For a deeper understanding of how this works, check out the video below to see the level in action: