Suggestion: Casino Music
No, I don't mean uploading your own music. I suggest (much like yoville/yo world) to have a selection of premade music tracks that you can purchase and apply to either your entire casino or on a per floor basis. It would help liven up the game a bit rather than having a singular music track for the entire game.

Also, you could use a jukebox or other music player on the floor to allow players to interact with and choose a track to listen to that the casino owner has purchased... for a small fee of course.

I know it's a lot of work, but I think it would be worth it in the end. There is a similar suggestion out there but I think this further expands on the idea.