When Nintendo created the Metroid series in 1986, they opened the floodgates for some of the best boss designs in gaming history. While Metroid set the foundation for these fights, later games perfected the formula. Featuring nods to Alien and Godzilla films, Nintendo drew from pop-culture to create massive and memorable boss fights.
However, creative inspiration only goes so far. While many of these boss fights indeed provided memorable experiences, others left the player frustrated. Despite their noblest intentions, certain design flaws can make a fight much less appealing. No matter how big the enemy, the nigh-unbeatable bounty hunter charges in against any foe.
With that said, please stay mindful of the Metroid series spoilers ahead.
10 Love: Ridley (All)
Samus' interstellar nemesis, the leader of the Zebesian Space Pirates, Ridley, debuted in the original Metroid. Originally a dragon that jumped in place spewing fireballs, beginning with Super Metroid, Ridley evolved into a flying menace armed with a variety of attacks. Ridley remains as Samus' most recognizable foe due to his frequent appearances as well as his role in the story: he murdered Samus' parents when she was just a child.
Save for his absence in Metroid II and Metroid Prime 2, this evil creature appears in nearly every one of Samus' adventures. Oftentimes a late-game boss, Ridley appears with high HP and a heavy arsenal of attacks. No matter what game he is in, whether in 2D or in 3D, the second his boss theme plays, it's time to gear up for a fight.
9 Hate: Kraid (Metroid)
Much like Ridley, Kraid debuted in the original Metroid. Looking vastly different than his recognizable appearance today, his unremarkable attack pattern involved slinging spikes at you. However, players who started with Super Metroid, or even saw him in Super Smash Bros. Melee, would be shocked to see what he was like in the original Metroid.
The creature spawned spikes from his torso which blocked from the front. This frustrating fight required Samus to morph into ball form and drop bombs without getting knocked into the acid. Only later games, like Super Metroid and Metroid: Zero Mission, would evolve Kraid into the Godzilla-sized menace that players enjoyed battling against.
8 Love: Quadraxis - Metroid Prime 2: Echoes
This massive machination offered a huge variety of attack patterns. One moment the player would fire away at it, with another part consisting of dropping bombs by its legs.
Quadraxis not only offered multiple layers of strategy but set a standard that would remain largely unmatched in the series. It was the best example of boss design in perhaps the entire Metroid Prime series. While the Prime series offered many bosses of varying boss strategy, the fight in the Sanctuary Fortress might have been the best by far.
7 Hate: Queen Metroid - Metroid II: Return of Samus
Honestly the only real boss in the game, the Queen Metroid stands between Samus and the end of her goal to extinguish all Metroids on Planet SR388. While the player fights hordes of Metroid evolution types throughout the game, these encounters become commonplace.
Unfortunately, the problem of this otherwise fierce encounter comes from a single design flaw. Players who ran out of missiles would not be able to progress. Without any way to replenish missiles, the players would be forced to restart the fight and conserve well for the fight. The remake, Metroid: Samus Returns, would correct this while evolving the queen's boss fight with new layers.
6 Love: Metroid Prime - Metroid Prime
The final boss and the source of the toxic material, Phazon, on Tallon IV, Metroid Prime was the evolution of Metroids having reached gargantuan proportions. This massive creature could change its elemental to block all but one of Samus' beams at a time. Featuring an armory of various weaponry, Samus was in for one of the toughest battles in the game.
Metroid Prime also featured a second form. Invulnerable to all weapons, Samus had to charge a Hyper Beam in the pool of Phazon in order to finish the creature off. Perhaps the best part of this fight came from the intense music and atmosphere it created.
5 Hate: Boost Guardian - Metroid Prime 2: Echoes
One of the two sinful creations of Metroid Prime 2, the Boost Guardian kept Samus' Boost Ball ability locked. In doing so, it could use its intense speed to hit Samus. This was known as an exceptionally difficult encounter.
Unfortunately, it was difficult for the wrong reasons. Being nearly impossible to strafe at the right time to evade the attack, the creature essentially punished the player just for fighting it.
4 Love: Omega Pirate - Metroid Prime
The sheer level of intensity coming from this boss fight stems heavily from its music. The ominous, foreboding theme as the creature marches at you, arm outstretched to absorb your beams, matches perfectly. The largest of all space pirates, this massive creature would deal nearly an energy tank worth of damage with a single blow.
Omega Pirate could cloak, fire various weaponry, and block Samus' own attacks. The environmental hazards, the Phazon, also kept Samus from freely moving around to dodge. Omega Pirate epitomized a dangerous encounter in a game filled with epic boss battles.
3 Hate: Spider Guardian - Metroid Prime 2: Echoes
The second of sinful creations in Metroid Prime 2, Spider Guardian also forced the player into a dire situation. Facing the player after they pick up the Spider Ball, they must fight the Spider Guardian on similar turf. Without proper dodging abilities, they're forced to move around with the Spider Ball's limited movement.
Unfortunately, this means the player cannot dodge attacks properly. Much like with the Boost Guardian, it becomes an exercise in frustration just for playing the game.
2 Love: Dark Samus - Metroid Prime 2: Echoes
Finally, some good news. Save for the aforementioned creatures, Metroid Prime 2: Echoes featured noteworthy encounters. One of them was perhaps the main antagonist, Dark Samus. Born from Metroid Prime and the fusion of Samus' suit, this malevolent being wanted revenge on Samus while spreading Phazon across the galaxy.
Dark Samus features similar beam attacks to Samus but with Phazon-embued skills. Plus you fight the creature several times throughout the game. The notable final encounter even includes an escape at the end featuring the original escape theme from Metroid.
1 Hate: MB - Metroid: Other M
In Metroid: Other M, MB, Madeline Bergman, was the android "clone" of Samus' archenemy, the Galactic Space Pirate leader Mother Brain. Originally created as the "daughter" of Melissa Bergman, she would eventually gain sentience. Rebelling against her scientist creators, MB went on a rampage across the Bottle Ship facility.
What makes this fight painful is that you never engage MB herself. You'll fight fierce, powerful creatures called Desbrachians while MB prepares to destroy everything around her. Once you finally manage to free yourself, you must aim for MB's head and finish the battle in one go. The fight is both short and extremely annoying to deal with. Fortunately, the player can choose to fight the post-game boss. Not only does it pay homage to Super Metroid but also features a more enjoyable final boss fight.