In the shell 2 core, get the Nikita first. Shoot it near the stairs in the second floor air dock. Go right,l eft, left, and left. Shoot down the fence. If the fence is down, shoot it again and go in the same direction. There could be a thing in the end of the wall. I think it is a Indian thing but I like to say it is a Easter Egg, its not really an Easter egg, I just got this from Gamefaqs.
To get sunglasses, you have to play the Tanker mission twice. Then Snake/Pliskin and Raiden will have sunglasses. Note: Snake/Pliskin and Raiden have different sunglasses, Snake's/Pliskin's sunglasses are cool, stylish, dark sunglasses. And Raiden's are big, rose-colored sunglasses.
Kill Giant Artic Soldier
In snakes fighting level you have to fight a giant artic soldier, from the first game. to kill him first stay out of the spot light coming from his head then when he's not looking shoot him in the head with a stinger missile-launcher. his head will fall off and he will send little robot-thingies down to find you stay out of sight and kill off the mini-robots quick then while the giant robots head is on the floor shoot it again into one of the holes in the back of arena like you were playing pin-ball just do this until he dies.
In deck 2 port, after shooting the semtex control boxes. run up the corridor until you see a guard, hide in the opening to the right until the guard gets close, then press L2 to peek around the corner, there is a metal bar on the wall next to you that will fall and make noise, causing the guard to investigate [dont worry, he wont see you if you keep your back against the wall]. during this time, another guard will walk down the hall, startling the other guard and causing them to look at each other [if you are trying to get dog tags you can pull off a double freeze [ONLY WITH THE M9]because the usp light will draw attention. from there, obtain their tags and tranquilize/kill them and your on your way.
Ninja Raiden and more
To get ninja raiden, complete 50% of his VR missions, which include hold up mode, weapon mode, etc. To get raiden x, complete 100% of raiden's VR missions. To get tuxedo snake, complete 50% of his VR missions. To get Metal Gear Solid 1 snake, you must complete all ninja raiden missions, all raiden missions, all raiden x missions, and all snake and tuxedo snake missions.
(Snake) after beating all the levels on the zako survival in VR missions, you now will face a mega genome from mgs1.to beat him, collect all the items laying around and pull out your stinger. now aim for his head and shoot, it will come off, now play some hockey and shoot it into one of the holes in the back wall. after this he will shoot mini genomes out of his headless neck, do this three times to beat him. (snake mgs1)again beat all of the zako survival levels, and again you will fight a giant genome...but way harder...or is he? first collect the m4 ammo, forget the stinger. quickly head to one of the back corners and aim up with your m4, you'll notice 4 target bars in a square pattern you can only hit the vertical bars and the horizontal bar closest to the giant soldier. hold L2 and R2 and shoot one out, then run to avoid his sticks he will then sneeze so hide behind the box in the center. repeat this until the three targets you can hit are destroyed, then a dust pan will fall on him and you complete the mission.
To beat Gurgolon (the giangantic beast in Raiden's last variety level)use your stinger to hit one of his targets .Afterwards, pull out an AK74-U and shoot the little blue thing swarming around where you shot him.The target will get smaller making it more difficult to hit.Eventually you will destroy the target, repeat until all targets are destroyed.Also theres a funny bit to the level:put on the BDU (enemy outfit) and equip the AK47-U. Let him trap you with his soundwaves and let him fire his eyebeams.Before it hits you, an explanation point pops above his head, which changes into a heart. He picks Raiden up and walks off with him as love music plays..... unfortunatly you fail the mission.