Well, the first thing I would do is change the pretty weird thumbnail and add more. Around 3 is enough. The icon is great, though. Next thing I would do is improve the quality. When the round is finished, a simple grey GUI appears with text. Make it fit the theme of the game. Also, some of the models look like free models and all use the same script to chase people.
One more thing, there is already an elevator game called The Normal Elevator. If you want player engagement, you need to be better than that game.
This is just how I would do it. Just remember, ask your friends or family to play test the game. It will come with the most feedback!
Yes, I have put 250 robux into sponsoring twice which only the first time made my robux back, while the second time made me none of my robux back unfortunately.
I think you have done everything in your power to make this active all you need is an eye catching advertisement and a good amount of robux to advertise the game.
Eye catching advertisements is one of the best ways to go, especially if the game is not something new and unique to the platform. However, if you want a lot of players, ads could turn out to be quite costly in terms of the amount of robux used in keeping the advertisements up and running, so that more players are able to find out about your game.