Guitar Hero: Warriors of Rock

This is simply unlocked by playing Quest Mode. In the quest mode path, select Johnny Napalm (1st on the path) and you will have to complete a number of stars by playing the songs in the setlist (7 in total) to make him transform to Warrior Johnny. It will show a progress bar to show how close you are to the transformation.

Upon transformation you will then be able to do an Encore song which is "Theme from Spiderman" by The Ramones.

Johnny Napalm's chapter is the first in the path in quest mode, and takes place in the now defunct CBGB's club. His power of choice is Speed Freak, it will make the minimum multiplier 2X and will never go back to 1X if you miss, however there's a mohawk meter on the multiplier if you keep it above 3X twice it'll dissapear though the minimum multiplier will be 2X. His setist is as follows:
(Note: It contains a variety of punk, rock, Glam, and alternitive)
* What do I get? - Buzzcocks
* We're not gonna take it - Twisted sister (From Guitar Hero: On Tour)
* Cherry Bomb (2010 Re-recording) - The Runaways
* Self Esteem - The offspring (Rock Band DLC)
* Motivation - Sum 41
* Re-Ignition (Live) - Bad Brains
* Black Rain - Soundgarden
* Theme from Spider-Man - The Ramones (Encore)
To get the achievement You need 35 power stars to transform, once that's done complete the encore song to Complete the transformation and get the achievement.