It's the year GC 232 (Galaxy Century Year 232). A huge war that had begun years and years before has divided the Milky Way and all of its natural resources have been exhausted. The Milky Way Galactic Council is forced to send a fleet of starships to a nearby planet by the name of UP457 in search of any resources that can replenish the ones lost during the battle.
However, during this mission, the fleet is destroyed by a race of half machine, half animal aliens referred to as "BIOMETAL" by the Galactic Council. One of the Council's super computers then calculates that the number of these "BIOMETALS" is increasing rapidly and will have the Milky Way completely taken over within 32 hours. So the Halbard, along with their fleet, WASP, are assigned to eliminate the hostile threat on UP457.
Weapon power-ups are gained by destroying pods and picking up the released power-ups. The player also has a Deflector Shield in the form of four spinning orbs that circle around the ship when the engaged (Known as the Gel Analog Mutant, a.k.a GAM). Charge power is drained when the GAM is active.
BIOMETAL is unique in that its soundtrack for the European and US versions was entirely created by techno group, 2 Unlimited (the selections used for BIOMETAL were remixes of songs from their 1991 album, "Get Ready!"). The Japanese version of the game featured an entirely different soundtrack which suits the dark mood better.
Not to be confused with the Biometals from Mega Man ZX.
- All Your Powers Combined: The fifth boss uses all the powers that your ship can use (sans missiles), but boosted Up to Eleven.
- Attack Its Weak Point: The fourth boss, and especially the Final Boss. For the final boss, it's the chest area, not the head.
- Antagonist Title: The Bio Metals are the bad guys here.
- Chain-Reaction Destruction: Larger enemies and bosses go down with that style with the explosions flying all over the place.
- Charge Meter: Shows how much shield energy you have left.
- Collision Damage: Notably averted with some enemies, such as the first boss.
- Combining Mecha: The second-to-last boss.
- Crowning Music of Awesome: Both the US soundtrack and the Japanese soundtracks. Such as "Dark Clouds" from the Japanese soundtrack.
- However, the US soundtrack is a Love It or Hate It- while some love it for the techno, many veterans despise it to the core.
- Deflector Shields: Your ship can produce a ring of round objects that circle your ship. These block enemy bullets, as well as damaging enemies who touch it. And you're going to need them.
- Degraded Boss: The second boss, a machine with flame-throwing Combat Tentacles, re-appeared as a Mini Boss of a later level.
- Demonic Spiders: The laser-shooting ships in stages 3 (who reappear again in later levels). Your shield is unable to block their devastating lasers, which will more often than not cost you a life or two.
- Difficulty Spike: The third level, which introduces those laser-shooting enemies, and a Damage Sponge Mini Boss
- Evil Is Visceral: Borderline- The titular enemies may look metallic grey, but they are more like a cross between flesh and metal.
- Excuse Plot: There are evil Mechanical Lifeforms running rampant, shoot them.
- Explosive Breeder: The computer analysis apparently shows the Biometals increasing in such a number that, if their planet is not destroyed in 32 hours, they would take over the entire galaxy!
- Frickin' Laser Beams: Your ship's laser weapon, as well as one of the weapons used by the Bio Metals.
- Fun with Acronyms: The GAM, which stands for Gel Analog Mutant. It's the name of your shield, by the way.
- Homing Projectile: One of your missile types gives you homing missiles.
- Horde of Alien Locusts: The Bio Metals are implied to be this.
- Incredibly Durable Enemies: And worse still, it's the Demonic Spiders who are.
- Kill It with Fire: The second boss tries this to you.
- Love It or Hate It: The US version's soundtrack is either a cool, heart-pumping techno, or a piece of garbage compared to the Japanese version. No exceptions.
- Many people who hate it state that the US soundtrack is a complete Soundtrack Dissonance, given the dark nature of the game and graphics.
- Luckily, My Shield Will Protect Me: Somewhat averted, as certain attacks pass through it, and some shots may sneak in between the gaps.
- Meaningful Name: The Bio Metals are part mechanical, part organic aliens.
- Mechanical Lifeforms: The Bio Metals.
- Mirror Boss: The second-to-last boss uses the three weapons that the player could use, except upgraded.
- Monstrosity Equals Weakness: The first boss is one of the largest enemies in the game, and he goes down the quickest.
- Mook Maker: Stage 4 has ones similar to those in the Gradius series.
- Multi Mook Melee: Right before the final boss, you have to deal with a swarm of lots of irritatingly durable rolling enemies that homed in on the player.
- Mutually Exclusive Powerups: The three primary weapon types (Laser, Spread and Wave), as well as your missile options.
- Nintendo Hard: The enemies sure love to spew loads of fast moving bullets... and many of them are tough to defeat.
- One-Hit-Point Wonder: Your ship can only take one hit to be destroyed, though your shields can mitigate most incoming fire.
- Orchestra Hit Techno Battle: The US version of the game had 2 Unlimited music as the game's soundtrack. Including the boss themes. Many people did not like the Soundtrack Dissonance it created, though.
- Reverse Shrapnel: Your shield weapon can be shot out like this.
- Segmented Serpent: Present as a regular enemy, as well as a boss. Obviously, go for the head.
- Shows Damage: The Final Boss. As you attack different parts of its body, you blow off its armour, revealing organic parts inside. However, you'll have to attack the chest area to actually damage it.
- Spread Shot: One of the three weapons you could get. It actually did rather decent damage.
- Shout-Out: In the US version, the protagonists are named "Kid Ray" and "Anita", the members of techno group 2 Unlimited.
- Soundtrack Dissonance: One of the main reasons why many veteran Shoot'Em Up players despise the US soundtrack.
- That One Boss: The miniboss of stage 3 takes a very long time to die without the laser. And the final boss also counts, it starts flooding the screen with lots of Hyper Destructive Bouncing Balls, making it a pain to avoid.
- Wave Motion Gun: The first boss has one, thankfully it's easy to avoid.
- When Plants Attack: The third boss is a plant-like organism that shoots out pollen and spores.