You can make all sorts of games in Roblox, from RPGs to battle royales to racing games. The editor,
which you download, has a lot of options and might be a good stepping stone to something like Unity or Unreal; it might seem intimidating at first but there are lots of example games built in that you can play around with to see how they work, plus there are plenty of tutorials on the Roblox site.

Roblox is a closed system—your games can only be published within the Roblox platform but there are a lot of users there who can play your game.

It’s also quite simple to make money from games on Roblox by making in-game items for people to buy, making your game paid, and having lots of players.