The Binding of Isaac
99 Achievements
250-260h
Steam
Mr. Mega!
Kids shouldnt play with matches...
39.4%
How to unlock the Mr. Mega! achievement in The Binding of Isaac - Definitive Guide
You unlock Mr. Mega by destroying 30 tinted/'X' rocks. These are usually pretty easy to spot, an example can be seen in the below picture.
http://imgur.com/ONHZrlQ
As soon as the 30th rock is destroyed you will be notified that you have unlocked it.
http://imgur.com/ONHZrlQ
As soon as the 30th rock is destroyed you will be notified that you have unlocked it.