All in all, I loved my experience. This game is absolutely amazing if you like dungeon crawlers and rhythm games. An absolute must have in my opinion. However, if you are considering buying the game or you are the developers, then I will give you the reason for why I am not giving the game a perfect five stars.
The DLC in this game is an absolute rip off, and that doesn't even put it to justice. For starters, the new characters can only be played in one game mode, which really stinks. That isn't even a storyline, its just a mode to kill things in. Next, the music isn't really "new music," but rather slightly modifying the genre of the music. Unfortunately, this was probably the DLC I was least disappointed with, which is kind of sad. Lastly, the new storyline for skull kid was a complete disaster in my opinion. I loved the idea of using various masks as weapons instead of a standard sword, spear, flail, etc. However, that is the only good thing I can bring myself to say about the story. It is way too hard, with absolutely no difficulty curve. Think of it was getting tossed into the deep end, but the devs thought it would be nice to tie an anvil to your back, with no way to take it off, and don't even get me started about the atrocities of the new "puzzles" that were added in this. It's more like "we are going to do different things to the room, and you need come up with your best guess as of to what we think you should do, even though the solution makes little to no sense."
Just to recap, since I can be kind of wordy, this is my views of the game in short: the games itself is great, only get the DLC if you want to waste money.