To unlock the following Trophies, complete the following tasks:
Unlockable: --- How to Unlock:
1ST MISSION MASTER (Bronze) --- Complete Mission 1 with no continue.
2ND MISSION MASTER (Bronze) --- Complete
Mission 2 with no continue.
3RD MISSION MASTER (Bronze) --- Complete
Mission 3 with no continue.
4TH MISSION MASTER (Bronze) --- Complete
Mission 4 with no continue.
ELEPHANT RESURRECTION (Bronze) --- Reach the icy cave's exit with the Elephant Slug.
FINAL MISSION MASTER (Bronze) --- Complete Final Mission with no continue.
HERE COMES HYAKUTARO ICHIMONJI! (Gold) --- Find and save Hyakutaro Ichimonji.
METAL SLUG ATTACK (Bronze) --- Defeat any boss in the game with the METAL SLUG ATTACK.
MISSION ALL COMPLETED (Bronze) --- Complete all the missions.
POINT HUNTER (Bronze) --- Achieve over 3,000,000 points.
ROUTE MASTER (Silver) --- Play all the routes.
SLUG MASTER (Bronze) --- Ride all the Slugs.
ZOMBIE MASTER (Silver) --- Clear Mission 2 as a zombie.
Stage 1: Hidden areas
Near the beginning of the first stage, you will see a submarine floating in a pool of water. Hold Down to walk into this area and hop into the sub to go to an underwater part of the stage. The next hidden area is at the part where the boat is located. Instead of getting on it, hop onto the ledge above it to find a secret hatch. Go inside to enter a cave-like part of the stage. Note: Every time you complete a secret area, you will go directly to the Crab Boss --- you cannot go in both hidden areas during the same turn.
Stage 2: Hidden area
The level containing the zombies has a secret and unique area. About the end of the middle part of the level, you will see a sign above a frozen-shut cave reading "ICEMAN". Walk to the left to go over here and shoot the ice wall blocking the entrance. Inside are numerous "ice men" and at the end of the cave is a buried Elephant Slug, frozen in the ground which you can free and ride.
Stage 4: Slave helper
Get to the second truck alive. Destroy the three helicopters and the truck. Jump over the truck and you will see a sandbag. Crouch and shoot backwards at the sandbag until you destroy it. There will be a tied up man underneath it. Free him and he will help you destroy the tanks and airplanes to come. His attack is similar to a Dragonball Z lightning ball strike.
Stage 2: Get Thunder Cloud
In the stage with the zombies, you can get the very helpful Thunder Cloud. Around the middle of the level, you will see a spot on a low area of ground where two prisoners are next to a man in a business suit. Hold Down/Forward to crawl down to this area and save them. Note: Enemies cannot get you down here. When you rescue the man in the suit, he will pull out a cell phone and call over two bodyguards with suitcases which contain a gold coin and the Thunder Cloud. To use it, just shoot your gun when the cloud hovers over an enemy.