Ride all the Slugs
Play all the routes
Clear Mission 2 as a zombie
Reach the icy cave's exit with the Elephant Slug
Defeat any boss in the game with the METAL SLUG ATTACK
Achieve over 3,000,000 points
Complete Final Mission with no continue
Complete all the missions
Complete Mission 4 with no continue
Find and save Hyakutaro Ichimonji
Complete Mission 3 with no continue
Complete Mission 2 with no continue
Complete Mission 1 with no continue
Start Mission 1