I mean it is not really worth using ads or sponsoring anymore because you can not get your sponsors and ads to the people under 13 but it your choose with the it. Also 10 robux will put you at the lowest part of showing your sponsor because bigger dev groups will put 100 of thousands of robux so you rather make a really good icon then it might bring more players in.
Yeah, 100 Robux isn’t really going to get you much. You’ll want at least R$1,000 if you want to actually advertise your game. Some will argue for higher, but if you just want people in your game for the launch window, R$1k is enough based on my personal experience.
Also, I’d recommend making a new icon, as most people probably won’t click on this one. You should make the focus a prisoner or a prison guard, that would definitely be better than an in-game screenshot of some doors.