For someone who isn't too big into rhythm games, Friday Night Funkin' (FNF) is definitely one of my favorite games. It stands out so much from other rhythm games with it's own charm, but has the Dance Dance Revolution gameplay to the bone. Unlike osu!mania, this is actually fairly easy for new players to pick up, as well as being free like osu!. One thing that really stands out to me most is the easy modding of the game, as well as access to the open source code. Whether you're a musician, artist, programmer, or all of them together, you can definitely make this into your own game.