Acevil on 06 May 2016
As for the OP: You don't need to change the original formula drastically, but you do need to make it better or near perfection. Similar to Uncharted 1 -> Uncharted 2. However Galaxy 2 and Uncharted 3 did not feel like drastic improvement over previous entries, but both still solid games, as they used the formula correctly.
However you do get Assassin Creed 2: Revelations or Modern Warfare 3 that just abused the formula, did nothing really, and was boring as all heck, and the next line of titles pay for it, because you start abusing formula that needed more work, but you chose to phone it in and when you did try, no one cares anymore.
