Nintendo’s NES Classic edition games list comes with 30 built-in titles, including Super Mario Bros, Donkey Kong, The Legend of Zelda and Punch Out, but many other games from that era are not available. However, hackers in Russia and Japan have already figured out how to add more games to the NES Classic Edition.

The hack originally appeared in the forums of Russian retro gaming community GBX in a YouTube video and step-by-step instructions. The subreddit r/NESClassicMods picked up on it and subjected their devices to the code, and with much success.

It’s not an easy process - but if you know about things like MD5 cases or config files, you may want to try it out. To get started, create a save file in Super Mario Bros. first slot. For further instructions on the NES Classic hack and how to play more games, follow the instructions posted by the hackers on PasteBin.

Nintendo first announced plans for the NES Classic edition in July. The Japanese firm launched the console in November, but of demand for the classic console was more than retailers could supply.