For a while now I've run a discord server called Slushie Arcade. In said server, I host a bunch of leaderboards for a curated selection of retro video games, mostly tracking high scores. I also (used to) do monthly challenges in specific games, sometimes with goals outside of just a high score.
Today, just now, minutes ago, I launched a new section of the arcade called The Notebooks. Basically, the goal is to pick out some more mysterious games and work together as a community to defeat them. It's kind of like when people get together to solve a game like Tunic, or the community notebooks that were all over Japanese arcades (and other places in the world, I'm sure).
If you want to get involved, click here and join the discord. It's been a lot of fun over this past year, and I'm excited to start this new activity.