How does roblox decide which games show up in the home sorts?

Nobody outside Roblox knows the exact formula, but it's mostly engagement, not visit count. How long people stay, whether they come back the next day, how many people who see the thumbnail actually click it. And it's personalised, so your home page isn't the same as mine. That's why a small game with good retention can show up over a bigger one that people quit after two minutes. Thumbnail and the first few minutes of gameplay do a lot of the heavy lifting.