Questions of making your own roblox game copy on Unity

I have recently been thinking about a future project i dont want to limit to just roblox. To my understanding, the roblox game is my own design and i own the rights for if i am correct. If i were to design and make a functionally identical game on game engines, what would be the legal ramifications on this, how would i go around having a “free” roblox version, and how would you personally do this.

Roblox doesnt technically own any content you produce on their site. So remaking your game in another engine would be fine as long as you dont have any roblox assets in the game.