You'll encounter six different types of Metroids within SR388's underground mazes. Read on for a quick overview of each form.
The initial form once the Metroid leaves its shell, these Alpha Metroids tend to fly around the screen while dive-bombing Samus. Pump their undersides with missiles to finish them off - score 5 missile hits to finish the job.
Gamma Metroids grow twice as large as Alphas and bear nastier melee attacks along with an electric lance. Keep your distance as the electric lance's range won't stop the beast coming up close and personal. Send 10 direct missile hits into this Metroid form to finish them off.
Zeta Metroids are tough fellas. Although small, they pack one heck of a punch. They'll float around the screen and often spit out fireballs, zipping back and forth while trying to get behind Samus and out of range. You'll have to pound Zeta Metroid's faces with 20 missiles for victory.
These massive Metroids emit electric spark balls from their mouths and fly around the screen randomly. Although they hover slower than Zeta forms, they're far stronger and require plenty more punishment to take down. Conquer them with 30 missiles to their face or back.
You'll only confront standard Metroids near the end of the game. Oddly these are the only ones that attempt to cling to Samus to drain her energy. But just like their Tourian cousins, freezing these Metroids with the Ice Beam then pumping them with 5 missiles will stop them in their tracks.
The biggest and baddest of all the Metroids, the Metroid Queen will be a very challenging fight.
Refer to Chapter 9 of the walkthrough for tactics to cook its hide.