I just noticed that when I click 2 player on the level menu and then click another level the white border stays around the 2 player button yet it goes on the other when you click a different 1... that's the only flaw in this game I've found so far... :)
this just isn't an achievement unlocked game. There's a storyline and the achievements aren't the only way to progress, which just isn't right... This isn't a bad game, but it's disappointing as it really doesn't live up to the first 2...
@RedsSun383 get all the gems on a level for a B, if you also get under a certain time, you get an A. The times will show up on all the levels when you hover your mouse over the "show times" bit of text on the bottom left of the main menu.
@papysadik the one you are missing is the dark guitar maniac. Play the songs with the purple skull symbol on them and get a bronze or better. Do this 3 songs in a row, and then play the song I just wanna burn. The boss will appear. Ignore ratchet200125's comment's ignorance to the detail in your comment