This week, the Metroid franchise celebrated its 39th anniversary on August 6th, 2025. To mark the occasion, the composer of the original Metroid on NES, Chip Tanaka, has shared his memories on Twitter about the debugging phase of the game. Our translation of his tweets, courtesy of Darts, is below.

One part of Metroid’s development that was particularly memorable to me was the final debugging phase.
There was one staff member who was much older and not actively involved in the production. The entire team was gathered in a single room, watching intently and cheering him on as he tried to beat the game. I composed the ending theme with that person in mind, sincerely wishing that he would be moved upon finishing it.
True story!

I think people who have played the game will agree, even after beating Mother Brain, the escape is surprisingly tough lol
The alarm is ringing loudly, you get stressed out and end up falling down, and so on.
So for that one tester, we kept making the monitor larger and the sound louder, which made it all the more impactful!
Everyone on the team had a lot of fun debugging the game.

Back in 2018, we had the privilege of being able to interview Tanaka-san about his work on Metroid. You can read our interview with him here.

Happy anniversary Metroid!

Source: Chip Tanaka