Album was composed by Shinsekai Gakkyoku Zatsugidan and was released on March 20, 2020. Soundtrack consists of 28 tracks tracks with duration over . Album was released by Wayô Records.
CD 1
| 1 | THE MILITARY SYSTEM (Operation Explanation, Ranking) | | |
| 2 | BARRACKS (Character Select) | | |
| 3 | Blue Water Fangs -The Island of Dr. Moreau- (Main Theme From METAL SLUG 3, Stage 1) | | |
| 4 | Marine Diver (Stage 1 Alternative Route〜Deep Sea) | | |
| 5 | The UNKNOWN WORLD (Stage 1 Alternative Route〜Core Facility, UFO Interior Passage 1) | | |
| 6 | STEEL BEAST 7BEATS (Boss Theme A) | | |
| 7 | Midnight Wandering (Stage 2) | | |
| 8 | Devil's Snow Cave (Stage 1 Alternative Route〜Cave of Ice) | | |
| 9 | METAMORPHOSIS (Boss Theme B) | | |
| 10 | The Shallow Sea (Stage 3) | | |
| 11 | Hard Water (Stage 3 Alternative Route〜Underground Channel) | | |
| 12 | ASSAULT THEME (Stage 3 Alternative Route〜Bridge, Stage 5-2) | | |
| 13 | Secret Factory (Stage 3 Alternative Route〜Armory) | | |
| 14 | Desert (Stage 4) | | |
| 15 | Pyramid (Stage 1 Alternative Route〜Pyramid) | | |
| 16 | THE CENOTAPH (Stage 4 Alternative Route〜Ancient Ruins) | | |
| 17 | The Japanese Army (Stage 4 Altenative Route〜Ex-military Hideout) | | |
| 18 | Into the Sky (Stage 5-1) | | |
| 19 | THE KIDNAPPING (Alien Appearance) | | |
| 20 | Into the Cosmos (The Void of Space) | | |
| 21 | KISS IN the DARK (Enemy UFO Interior) | | |
| 22 | FIRST CONTACT (UFO Interior Passage 2) | | |
| 23 | BIOINFORMATICS (UFO Interior Passage 2) | | |
| 24 | ESCAPE (UFO Escape) | | |
| 25 | FINAL ATTACK (Final Boss) | | |
| 26 | END TITLE (Final Production〜Staff Roll) | | |
| 27 | GRAVESTONE (Game Over) | | |
| 28 | CARRY OUT (Stage Clear) | | |
