Best Buy: INSIDE/LIMBO Double Pack PlayStation 4 71501930
Limbo Guide and Walkthrough
The Secret Level In Limbo That You May Have Missed
The extra hidden secret eggs in Limbo that is not unknown to many (read description for explanation of this. I provided a link to the Youtube video showing them being collected) :
Limbo walkthrough and achievement guide: Page 2 | GamesRadar+