At the end of the Extra Ops "Deja Vu", you'll be presented with questions regarding to the original Metal Gear Solid game released on 1998. Deja Vu is a mission that's exclusive to PS3 and PS4 version of the game. The set of questions differ for completing the mission in Normal or Hard difficulties. Answering the questions perfectly will unlock the Classic Snake skin on Normal and Cyborg Ninja (Grey Fox) skin on Hard.
Normal
Q1: MGS1 featured Solid Snake infiltrating which island?
A: Shadow Moses
Q2: The remote-controlled missile is known by which nickname?
A: Nikita
Q3: Who did you need to call on the Codec in order to save your progress?
A: Mei Ling
Q4: The Next-Generation Special Forces who took part in the uprising with FOXHOUND were given what treatment?
A: Gene therapy
Q5: On which floor of the Nuclear Warhead Storage Building was Otacon's lab located?
A: 2nd Floor Basement
Q6: What was the Cyborg Ninja's True Identity?
A: Frank Jaeger
Q7: Before being called back into action for the mission, Snake lived in Alaska as a...?
A: Musher
Q8: What was the maximum load of the elevator in Communications Tower B?
A: 650 lbs (300 kilograms)
Q9: What type of storage media did the ArmsTech president give Snake?
A: Optical Disk
Q10: What is the title of the ending theme?
A: The Best is Yet to Come
Hard
Q1: What did Snake call Otacon's love for a certain female character?
A: Stockholm Syndrome
Q2: When Otacon visited Snake at his cell after he was captured, he gave him what level of security card?
A: Level 6
Q3: Which boss character was NOT a member of FOXHOUND?
A: The Cyborg Ninja
Q4: What was the name of the studio (later renamed Kojima Productions) that developed MGS1?
A: KCE (Konami Computer Entertainment) Japan
Q5: Who did Otacon fall in love with in MGS1?
A: Sniper Wolf
Q6: How did they censor Johnny Sasaki's privates in the U.S. release of MGS1?
A: Pixelization
Q7: Snake attempted to give Meryl a handgun of what caliber?
A: .45
Q8: After escaping the base, Snake and Meryl encounter a family of which type of animal?
A: Caribou
Q9: In total, how many prototypes of the stealth camouflage did Otacon build?
A: 5
Q10: What did the "P.A.L." in "P.A.L. Key" stand for?
A: Permissive Action Link