Last April, Ganon11 and his team held a charity marathon of the Metroid series. They ended up raising $178 for the Connecticut Children’s Medical Center. They’re going to hold another marathon soon, again for the CCMC through Extra Life, with a goal of $1000. The marathon starts at 12:00 PM EST on Friday, September 1, and they estimate they will be playing for 72 hours straight until around noon EST on Monday, September 4.
You can find them at metroidmarathon.com, or on Twitch via twitch.tv/Ganon11, although that stream will be embedded on the website. They will be playing every Metroid game in the series released thus far. If they meet their goal, there may even be a special surprise.
Source: Metroid Marathon