it's better to go in your way, i meant about indie game development. I'm new to unity but I know about stuffs like this! Unity is a good option! If you know c#, the best. Orelse, try bolt!!! It's drag and drop, very easy!!!
Orelse try bolt! And music: Make your own. Orelse look in web, it's ok! It's according to your mind that makes the best games. Your creativity must touch the players mind! The theme is what it counts! The player also expects it! got it?
By the way, I'm still studying unity and if I'm late, I'll use scrtch.org.