U.S. Congresswoman Alexandria Ocasio-Cortez made a surprise appearance during a Twitch streamer’s “Donkey Kong 64” charity marathon this weekend.

Hbomberguy, whose real name is Harry Brewis, was raising money for Mermaids, a U.K.-based nonprofit that supports children with gender dysphoria. He apparently did this out of “spite,” according to a YouTube video announcing the event. When Mermaids was designated funding by the U.K.’s National Lottery, a TV writer named Graham Linehan reportedly encouraged people to email the organization in protest. Mermaids’ funding is now under review.

“So well done, Graham!” Brewis said in the video. “You have a massive audience and the power to choose to fight for progress in all the many forms we need in the world right now and you used it to make sure some children won’t have access to helpful resources.”

Brewis decided to raise money for Mermaids himself and began streaming the classic Nintendo 64 platformer “Donkey Kong 64” — a game he regretted never beating as a kid — on Jan. 18. By the time the marathon wrapped up (nearly 58 hours later), he 100% completed the game and raised over $340,000.

Watch DONKEY KONG 64 CHARITY NIGHTMARE For MERMAIDS from Hbomberguy on www.twitch.tv

Well-known gaming figures like “Doom” creator John Romero and critic Jim Sterling made cameo appearances during the broadcast, along with activist Chelsea Manning and Rep. Ocasio-Cortez, who mentioned the Mermaids fundraiser on Twitter after criticizing recent comments made by “The West Wing” writer Aaron Sorkin about transgender bathrooms. Brewis and Ocasio-Cortez talked about the current U.S. government shutdown, trans rights, and the congresswoman’s call for a 70% marginal tax rate before chatting about video games. While Ocasio-Cortez never owned a Nintendo 64, she said she’d often go to a cousin’s house and watch him play games like “Super Mario 64” and “Pokémon Snap.” She believes it’s “probably the best system out of all of them.”

Following the stream, Brewis tweeted that all Twitch subscriptions and bits will go to Mermaids, while any remaining subs will “go towards a fund for trans, nonbinary and others who need direct help. Will announce details when we figure it out and I’m alive again.”