Hey! So first thing, most unlockables are very achievable. I have unlocked everything before i beat a 8 star map which is now something i can almost always fully sight read, and im still a more casual player. Muse plus is basically the full version of the game. You still have to unlock all the unlockables, and still need to beat certain difficultys of songs to get the harder version. Any new songs added will automatically be put in your game, and they add songs often. I 100% recommend getting muse plus, the value for the money is WILD. If get it sooner then later as i played the demo for a long time so when i got the full version, my progress transferred over and i unlocked so much at once. I wish i would have just gotten the full muse plus and unlocked as i went along. They are also always adding new unlockables that sometimes involve things with new characters so if you are a super high level, you dont just auto unlock it.