History YMMV / MetroidZeroMission

** Mecha-Ridley becomes one on a 15% or 100% run. His arm slash is highly telegraphed, but it has such a large range that the only practical way to dodge it is to have been out of its way beforehand. Where's out of the way? Up in the air, so you pretty much have to spam Space Jump for the entire fight. His worst attack is his EyeLasers, since they fire in random directions, travel quickly, and can't be blocked through Screw Attack. Shooting his core takes good timing, and you're backed against a wall the entire time. He only seems easy because he's a GlassCannon, and thus most player don't have to face the worst of his attacks. Fight him for an extended time, and Mecha-Ridley becomes a nightmare.

* AntiClimaxBoss: [[spoiler:Mecha-Ridley]] is incredibly easy for a final boss, and can feel like an anti-climax for those unaware that getting 100% of all items triples his difficulty level.

** The Chozo Mural is also pretty difficult. You have to shoot it in the glowing orb he's holding whenever it displays a certain symbol, but all the other times it shows you, meaning shooting it then means hurting yourself. You take a lot of damage due to lacking your Power Suit, and can only fire when your pistol is at full charge. Its bouncing is hard to avoid, and the area is pretty small. Plus, it hurls lightning at you, and it's hard to watch for the flashing cues that signal whether it's just a single bolt of lightning or twin bolts that climb up the floor and wall. Defeating it takes a lot of mental juggling.

** The Chozo Mural is also pretty difficult. You have to shoot it in the glowing orb he's holding whenever it displays a certain symbol, but all the other times it shows you, meaning shooting it then means hurting yourself. You take a lot of damage due to lacking your Power Suit, and can only fire when your pistol is at full charge. Its bouncing is hard to avoid, and the area is pretty small. Plus, it hurls lightning at you, and it's hard to watch for the flashing cues that signal whether it's just a single bolt of lightning or twin bolts that climb up the floor and wall. Defeating him takes a lot of mental juggling.

* ThatOneBoss: Mother Brain. Let us count the ways. First off, you fight her while standing over a pit of lava. And you don't get a platform to stand on. Instead you get just ''two measly blocks'' which ''aren't'' connected to each other that barely let you take more than two steps on either before you fall. Stand in one spot for too long, and you get targeted by Rinkas that will knock you off, and, just to be petty, are Red Rinkas that aren't guaranteed to give you any health or missiles. Surrounding the area are turrets that fire in random directions, making jumping risky because it's impossible to predict when and where they'll shoot. Even if you made sure to replenish your missiles after destroying all the Zebetite barriers blocking the way to her, you still have to waste a ton of them trying to crack her tank. Also, remember how in the previous games Mother Brain was just a sitting duck who wouldn't fight you as you shot her? Well, say goodbye to that; now she has a {{Eye Beam|s}} of doom that fires every time you damage her or fall off the blocks. God help you if you try fighting her in a 15% run.

* ThatOneBoss: Mother Brain. Let us count the ways. First off, you fight her while standing over a pit of lava. And you don't get a platform to stand on. Instead you get just ''two measly blocks'' which ''aren't'' connected to each other that barely let you take more than two steps on either before you fall. Stand in one spot for too long, and you get targeted by Rinkas that will knock you off, and, just to be petty, are Red Rinkas that aren't guaranteed to give you any health or missiles. Surrounding the area are turrets that fire in random directions, making jumping risky because it's impossible to predict when and where they'll shoot. Even if you made sure to replenish your missiles after destroying all the Zebetite barriers blocking the way to her, you still have to waste a ton of them trying to crack her tank. Also, remember how in the previous games Mother Brain was just a sitting duck who wouldn't fight you as you shoot her? Well, say goodbye to that; now she has a {{Eye Beam|s}} of doom that fires every time you damage her or fall off the blocks. God help you if you try fighting her in a 15% run.

* ThatOneBoss: Mother Brain. Let us count the ways. First off, you fight her while standing over a pit of lava. And you don't get a platform to stand on. Instead you get just ''two measly blocks'' which ''aren't'' connected to each other that barely let you take more than two steps on either before you fall. Stand in one spot for too long, and you get targeted by Rinkas that will knock you off, and, just to be petty, are Red Rinkas that aren't guaranteed to give you any health or missiles. Surrounding the area are turrets that fire in random directions, making jumping risky because it's impossible to predict when and where they'll shoot. Even if you made sure to replenish your missiles after destroying all the Zebetite barriers blocking the way to her, you still have to waste a ton of them trying to crack her tank. Also, remember how Mother Brain was just a sitting duck who wouldn't fight you as you shoot her in the previous games? Well, say goodbye to that; now she has a {{Eye Beam|s}} of doom that fires every time you damage her or fall off the blocks. God help you if you try fighting her in a 15% run.

* ThatOneBoss: Mother Brain. Let us count the ways. First off, you fight her while standing over a pit of lava. And you don't get a platform to stand on. Instead you get just ''two measly blocks'' which ''aren't'' connected to each other that barely let you take more than two steps on either before you fall. Stand in one spot for too long, and you get targeted by Rinkas that will knock you off, and, just to be petty, are Red Rinkas that aren't guaranteed to give you any health or missiles. Surrounding the area are turrets that fire in random directions. Even if you made sure to replenish your missiles after destroying all the Zebetite barriers blocking the way to her, you still have to waste a ton of them trying to crack her tank. Also, remember how Mother Brain was just a sitting duck who wouldn't fight you as you shoot her in the previous games? Well, say goodbye to that; now she has a {{Eye Beam|s}} of doom that fires every time you damage her or fall off the blocks. God help you if you try fighting her in a 15% run.

* ThatOneBoss: Mother Brain. Let us count the ways. First off, you fight her while standing over a pit of lava. And you don't get a platform to stand on. Instead you get just ''two measly blocks'' that barely let you take more than two steps before you fall. Stand in one spot for too long, and you get targeted by Rinkas that will knock you off, and, just to be petty, are Red Rinkas that aren't guaranteed to give you any health or missiles. Surrounding the area are turrets that fire in random directions. Even if you made sure to replenish your missiles after destroying all the Zebetite barriers blocking the way to her, you still have to waste a ton of them trying to crack her tank. Also, remember how Mother Brain was just a sitting duck who wouldn't fight you as you shoot her in the previous games? Well, say goodbye to that; now she has a {{Eye Beam|s}} of doom that fires every time you damage her or fall off the blocks. God help you if you try fighting her in a 15% run.

* [[DemonicSpiders Demonic Metroids]]: Metroids are horrifically difficult to fight. Freezing them wears off faster than most enemies, and it's only when they're frozen that they can be damaged, and then only with missiles. If one latches onto you, you can deploy a bomb to make it let go, but drop too many and you'll accidentally bomb jump back into its mouth. They come in groups, so you might freeze one Metroid only to find yourself backed in a corner with another waiting on the other side of its frozen friend, ready to grab you as soon as you kill it. Add this to hazards like lava in some of the rooms, Rinkas that are a nuisance, and thus it only takes one trip from a missed obstacle to fall and become Metroid food. Play on Hard and/or a 15% run, and you'll soon find yourself out of Missiles, desperately re-freezing every Metroid surrounding you and picking off every Rinka in hopes that it drops a missile this time. Did we mention the doors lock so you that you can't leave the room?

* GoodBadBugs: A few are mentioned in ArtificialStupidity on the main page. Also, it turns it's indeed possible [[http://www.youtube.com/watch?v=OnfKCdKJz6I to escape Tourian the other way]].

Click [[http://tvtropes.org/pmwiki/pmwiki.php/YMMV/Metroid1 here]] for the YMMV page on the original game.

!!Specific to the original game ''Metroid''
* CrazyAwesome: Inputting the password "[[http://www.youtube.com/watch?v=x3UyVylP7AI ENGAGE RIDLEY MOTHER FUCKER]]". The results are hilarious, if suicidal.
* ItWasHisSled: Someone turns out to be a woman in the game. [[SarcasmMode Ridley, I think]]?
* MemeticMutation: The "Justin Bailey" password[[note]]which actually gets inputted in-game as "JUSTIN BAILEY ------ ------"[[/note]] spawns Samus in her pink leotard with almost all her power-ups. Theories have abounded about who Justin Bailey is or it's a reference to an Australian phrase "just in a bailey (swimsuit)", but it's been confirmed the password was an accident.
* SeinfeldIsUnfunny: Playing the original game decades later can be rife with frustration, as Samus's jumping is floaty, you take lots of knockback from damage, there's no map you can reference, and you can only save when you die, after which you must memorize a complicated password and then grind back all the health you've lost.

!!Specific to the remake ''Metroid: Zero Mission''

** The Chozo Mural is also pretty difficult. You have to shoot him in the glowing orb he's holding whenever it displays a certain symbol, but all the other times it shows you, meaning shooting it then means hurting yourself. You take a lot of damage due to lacking your Power Suit, and can only fire when your pistol is at full charge. Plus, he hurls lightning at you, and it's hard to watch for the flashing cues that signal whether it's just a single bolt of lightning or twin bolts that climb up the floor and wall. Defeating him takes a lot of mental juggling.

* ThatOneBoss: Mother Brain. Let us count the ways. First off, you fight her while standing over a pit of lava. And you don't get a platform to stand on. Instead you get just ''two measly blocks'' that barely let you take more than two steps before you fall. Stand in one spot for too long, and you get targeted by Rinkas that will knock you off, and, just to be petty, are Red Rinkas that aren't guaranteed to give you any health or missiles. Surrounding the area are turrets that fire in random directions. Even if you made sure to replenish your missiles after destroying all the Zebetite barriers blocking the way to her, you still have to waste a ton of them trying to crack her tank. Also, remember how Mother Brain was just a sitting duck who wouldn't fight you as you shoot her in the previous games? Well, say goodbye to that; now she has a {{Eye Beam|s}} of doom that fires every time you damage her or fall off the blocks. God help you if you try fighting her in a 15% run.

* AntiClimaxBoss: Mecha-Ridley is incredibly easy for a final boss, and can feel like an anti-climax for those unaware that getting 100% of all items triples his difficulty level.

* SeinfieldIsUnfunny: Playing the original game decades later can be rife with frustration, as Samus's jumping is floaty, you take lots of knockback from damage, there's no map you can reference, and you can only save when you die, after which you must memorize a complicated password and then grind back all the health you've lost.

* CrazyAwesome: [[http://www.youtube.com/watch?v=x3UyVylP7AI ENGAGE RIDLEY MOTHER FUCKER]]

* ThatOneBoss: Mother Brain. Let us count the ways. First off, you fight her while standing over a pit of lava. And you don't get a platform to stand on. Instead you get just ''two measly blocks'' that barely let you take more than two steps before you fall. Stand in one spot for too long, and you get targeted by Rinkas that will knock you off, and, just to be petty, are Red Rinkas that aren't guaranteed to give you any health or missiles. Surrounding the area are turrets that fire in random directions. Even if you made sure to replenish your missiles from destroying all the Zebetite barriers blocking the way to her, you still have to waste a ton of them trying to crack her tank. Also, remember how Mother Brain wouldn't fight you in the previous games when you blew up her tank? Well, say goodbye to that; now she has a {{Eye Beam|s}} of doom that fires every time you damage her or fall off the blocks. God help you if you try fighting her in a 15% run.

* [[DemonicSpiders Demonic Metroids]]: Metroids are horrifically difficult to fight. Freezing them wears off faster than most enemies, and it's only when they're frozen that they can be damaged, and then only with missiles. If one latches onto you, you can deploy a bomb to make it let go, but drop too many and you'll accidentally bomb jump back into its mouth. They come in groups, so you might freeze one Metroid only to find yourself backed in a corner with another waiting on the other side of its frozen friend, ready to grab you as soon as you kill it. Add this to hazards like lava in some of the rooms, Rinkas that are a nuisance, and thus it only takes one trip from a missed obstacle to fall and become Metroid food. Play on Hard and/or a 15% run, and you'll soon find yourself out of Missiles, desperately re-freezing every Metroid surrounding you and picking off every Rinka in hopes that it drops a missile this time. Did we mention the doors lock so you that you can't leave the room?

* [[DemonicSpiders Demonic Metroids]]: Metroids are horrifically difficult to fight. Freezing them wears off faster than most enemies, and it's only when they're frozen that they can be damaged, and then only with missiles. If one latches onto you, you can deploy a bomb to make it let go, but drop too many and you'll accidentally bomb jump back into its mouth. They come in groups, so you might freeze one Metroid only to find yourself backed in a corner with another waiting on the other side of its frozen friend, ready to grab you as soon as you kill it. Add this to hazards like lava in some of the rooms, Rinkas that are a nuisance just annoying enough for you to trip on one and thus become Metroid food. Play on Hard and/or a 15% run, and you'll soon find yourself out of Missiles, desperately re-freezing every Metroid surrounding you and picking off every Rinka in hopes that it drops a missile this time. Did we mention the doors lock so you that you can't leave the room?

* [[DemonicSpiders Demonic Metroids]]: Metroids are horrifically difficult to fight. Freezing them wears off faster than most enemies, and it's only when they're frozen that they can be damaged, and then only with missiles. If one latches onto you, you can deploy a bomb to make it let go, but drop too many and you'll accidentally bomb jump back into its mouth. They come in group, so you might freeze one Metroid only to find yourself backed in a corner with another waiting on the other side of its frozen friend, ready to grab you as soon as you kill it. Add this to hazards like lava in some of the rooms, Rinkas that are a nuisance just annoying enough for you to trip on one and thus become Metroid food. Play on Hard and/or a 15% run, and you'll soon find yourself out of Missiles, desperately re-freezing every Metroid surrounding you and picking off every Rinka in hopes that it drops a missile this time. Did we mention the doors lock so you that you can't leave the room?