I grew up playing Roblox games (and later scripting in Studio) and the most memorable aspect was how surreal everything was. Most of the games were mishmashes of pre-existing assets, puerile humor, and pop culture references.

I remember one game in which you started off on a massive platform full of food, and had to shovel the food onto a conveyor belt that led into a giant person's mouth. If you yourself fell onto the conveyor belt, you'd be treated to a grand tour of the person's digestive system before being turned to poop and dropped into the toilet bowl. Inside the toilet there was an obstacle course, and at the end of this obstacle course there was an array of fighter jets that you could use to get back onto the food platform. The jets didn't have throttle: they either went super fast or not at all. So the poop-people would bail out of their planes in mid-air, and the jet would crash into the baseplate, usually killing someone below.

This was back when there was no way for developers to monetize their games. Some games had "VIP T-shirts" that gave you tools or allowed you to enter a special room, but devs had neither the technical ability nor the incentive to "do it for the money". Most games were like the one I described: bizarre one-off projects created with the intent of showing something really cool. A few "classics" kept stable player-bases, but for the most part the front page was a constant churn of weirdness.

I've still never seen anything quite like it.