Naturally, a dungeon crawler infamous for being Nintendo Hard is going to have levels that really irritate players.
Etrian Odyssey and The Millennium Girl
- The Primitive Jungle isn't looked upon fondly by most players. The enemies that populate the stratum use ailments a lot more often, and this stratum introduces damage tiles, putting a lot of strain on your Medic's TP or mandating a good supply of healing items to traverse. But above all, it's a bland change of scenery, as the jungle has just as much greenery as the Emerald Grove, just darker.
- B20F, the finale of the Sandy Barrens and the Last Stand of the Forest Folk, is a Marathon Level to the point where the whole floor can charitably be called the stratum's boss. The boss itself, Iwaoropenelep, is visible at the start, but revives upon being killed until you kill over a dozen FOEs spread across the floor without leaving to rest at the innnote . Even if the party can reliably kill the FOEs by this point, having to take them all on in one trip while crawling back to the healing spring on an earlier floor as needed adds a lot of stress. While there are no random encounters, the floor's interconnected corridors make it easy for one or more enemies to join in on a single fight if one is started in a bad spot, which becomes even worse when Iwaoropenelep starts moving through the maze after about half of them are killed. Even after defeating everything, there's still dealing with Iwaoropenelep itself, who's That One Boss in its own right and can render all that hard work for naught if you don't backtrack and save at the Geomagnetic Pole. Untold, to many's relief, overhauled the floor into a much less strenuous Stealth-Based Mission.
- The Claret Hollows is a Brutal Bonus Level and might as well be That One Stratum of the whole series because its floor design will push the player's patience to the limit. Not helping matters is that the first game has a very primitive mapping system so it's very difficult to construct a good map to help you through. You're likely to hit the icon cap while mapping the floors out.
- B26F is rife with one-way passageways that lock you into a dead end that leads into a warp that returns you to the beginning. Its parallel in The Millennium Girl reduces the number of duds.
- B27F mostly consists of a wide open area, littered with invisible pitfalls that drop you into a large open dead-end of the next floor. Said next floor is littered with damage tiles and fast FOEs that can swoop in on your position and ambush you. The intended way to navigate the floor is by following the movement paths of the FOEs, but this is easy to miss entirely or screw up for a while by killing them, and even with that knowledge some trial-and-error is inevitable, given that there's 300 (317 if including inaccessible zone) pitfalls to navigate around! The remake staggers the pitfalls' locations, makes them visible, but also partially obscures them with a Blackout Basement element to make the experience more fair.
- B29F is the most tedious teleporter maze, perhaps in the entire series. With more warps and destinations than your icon cap can handle, you will easily find yourself lost and driven Half-Mad From Self-Doubt. Again, its parallel in the remake only slightly simplifies the maze.
- To top it all off, in the original, the only shortcut in the stratum is right at the very end, linking the beginning of the stratum to the doors to the ultimate Superboss, so if you're making any return trips you must traverse the floors in their entirety. Mercifully, the remake adds shortcuts in each floor to shorten your return trips, in addition to the whole Floor Jump mechanic letting you focus on mapping out new ground.
Etrian Odyssey II: Heroes of Lagaard and The Fafnir Knight
- B3F of Ginnungagap in The Fafnir Knight. When you enter for the first time, you're forced to undergo a trial to the very end. You are unable to use Ariadne Threads to escape the floor (they'll instead take you to the beginning of the floor), and the the F.O.E. of the floor is utterly relentless, chasing you down and preventing you from escaping if it engages you in a battle note . Thankfully, saves are disabled, so you can't become permanently stuck in it, but the alternative of losing your progress still stings a lot.
Etrian Odyssey III: The Drowned City
- B10F in the Molten Caves is a slog of a floor, owing to its massive amount of damage tiles and wide-open rooms full of Mother Dragons (which try to close in on the party while they're in battle unless it's nighttime). The huge central room housing the Hall of Conviction is also notorious for forcing players to trudge across an expanse of nothing to reach the various shortcuts leading down to parts of B11F. It's a small mercy that there aren't any damage tiles in the second half of the stratum.
- The fifth stratum, the Porcelain Forest, is where level design puts your mapping skills to the test. Several rooms disable auto-mapping, forcing you to track your party's location manually — woe betide the player who got caught in a random encounter and lost their bearings. The stratum's final floor, right before the final Route Boss, mixes the anti-mapping areas with FOE puzzles and muddy tiles, and forces you to go through them multiple times if you happened to take the wrong warp gate that sets you back to familiar territory.
- If the anti-mapping regions of the fifth stratum tested your patience enough, the sixth stratum pushes them to the limit. B22F is mostly anti-mapping regions and has pitfalls that drop you into B23F and force you to redo the previous segment. B24F combines mapless regions with a one-way door maze and tiles that spin you around to disorient you.
Etrian Odyssey IV: Legends of the Titan
- The Golden Lair, the primary maze of the third land, is one of the most mechanically complex dungeons in the series. The main gimmick of the area is Ice Stakes, special gathering items taken from Chop points and used to break the burning scales blocking the way. Only two Ice Stakes can be obtained from each point every day without gathering skills, they melt upon leaving, and the scales respawn every day, making it easy to run out and have to leave until more shortcuts are unlocked. The heat from the scales doubles as damage tiles, meaning the dungeon drains health fairly fast as well. Each floor of the labyrinth contains a massive scale pile that cools the scales and freezes all water tiles when destroyed (though it respawns after a week, adding additional time pressure), making it easier to navigate but also making the Plated Chaser FOEs much more dangerous by allowing them to slide on the ice to reach you quickly. Lastly, even finding where to go can be confusing, as the dungeon is effectively split in two by its two entrances with both areas needing to be explored thoroughly. All of this on top of the increased strength of encounters means that it can be a very arduous dungeon until you beat the mid-boss and unlock subclassing. It isn't any easier when revisited as part of opening the Forgotten Capital, with its hidden area sporting even harder scale/ice puzzles and some of the most lethal enemy formations in the game.
Etrian Odyssey V: Beyond the Myth
- 25F is the epitome of the rather annoying anti-gravity mechanic of the 5th Stratum. For context, there are switches throughout the stratum that cause your party to levitate, and while they are in this state, moving will cause you to keep moving in that direction until you hit something, such as a wall, door, or an FOE; functionally, it's like applying Frictionless Ice to the entire dungeon, except it also lets you cross the pits in the floor. 25F in particular requires you to trigger a switch and go through multiple FOE-infested rooms, and the rooms are big and difficult to map when your movement options are so limited. Eventually you hit a second gravity switch, the second one in the entire floor (whereas previous floors have switches at more frequent intervals), to land back on the floor and have to backtrack through all of those rooms full of FOEs just to make your way to the Final Boss.
- 29F is not just any teleporter maze — it's a teleporter maze that sends the player all the way back through the unexplored parts of the earlier floors and back up again, traversing rooms with FOEs that frustrate a player trying to thoroughly fill out their map. Shortcuts that speed up return trips are scarce, and from time to time there will be certain teleporters positioned to send the player back to already-explored regions of the map if they enter it from the wrong angle, wasting a lot of time returning to where they left off. To top it off, near the end is a door with a teleporter placed directly behind it that sets the player back by a good amount, and if they forgot to unlock a shortcut not too far away, well...
Etrian Odyssey Nexus
- The main dungeons of Nexus draw from previous strata in the series but don't overstay their welcome. The side dungeons may be only one floor long, but they tend to feature annoying gimmicks that discourage exploration when they're immediately unlocked:
- The Giant's Ruin can get very irritating because of the deliberately inflated encounter rate. Not helping matters is that this is done to set up FOE gimmicks, as they are statues that will not move or engage in battle until the player already is in battle, but can still block chokepoints at the wrong times. Also, damage tiles there are guaranteed to initiate a battle. To make matters worse, the random monsters have markedly more HP than any non-FOE enemy you've fought up until that point, which gives those statues more time to catch up to you.
- The Blossom Bridge in throws some extremely confusing floating platform puzzles at you that can take hours of frustration to figure out, assuming you don't just give up trying to figure out the logic behind each puzzle. It also has Big Moths, who can generate a swift Game Over by using Confusion Dust to spread Panic to your party so that they can quickly kill themselves while being unable to evade the enemies' attacks.
- The Illusory Woods makes for a rather rude awakening in the transition to the Nexus postgame. Before you even start, the game warns you to make sure you have Ariadne Threads on hand. That's because the FOEs here can chase you everywhere and can even pass through walls. Once one of them has been alerted to your presence there's no escaping it except by returning to town. To make matters worse, the place is infested with Demonic Spiders that give the FOE more time to close in on you.
