knytt stories has one of the most accessible level editors i’ve encountered (though not necessarily one of the best designed); because of that, the levels that come from it provide a lot of insight into the state of amateur level design. there are the occasional flashes of insight, of personality and charm, experimental ideas, but there are also a lot of very similiar mistakes. the most heart-breaking is the flat room: this is a screen in which the player simply runs left to right (or right to left) along a flat, unbroken floor. juni, the protagonist of knytt stories, can jump, climb walls, and float through the air. the flat room enables her to do none of these things.
the shape doesn’t fit the play. knytt stories is about climbing, and so there’s a lot of vertical motion in nifflas’s (the author of knytt stories) levels. take his “underwater adventure” as an example: it begins with the player travelling deeper and deeper under the ocean, then climbing all the way back up to the surface. not only does this fit the “vocabulary” of the game’s protagonist, it also gives the level a shape that suits its story. from the water’s surface, down into the darkest depths, then back to the surface. there’s a symmetry there that provides a sense of closure. an empty hallway does nothing to characterize a level or its protagonist.
castlevania on the nintendo begins with a flat hallway. (see the full level, courtesy rick n. burns of nesmaps.com.) but halfway through the level that horizontalness is broken forcefully: the designers drop a vertical brick wall in the middle of a room. with a staircase visible on either side. the player must make a detour to the basement of the castle to circumnavigate the wall. what i find interesting is how the path to the basement staircase is broken up with both a change in platform height and an intermediary staircase. the player also has to walk right to meet the wall before travelling left to the staircase: the player is forced to acknowledge the obstacle.
(there’s also a piece of life-restoring meat hidden in the wall, for the player who investigates it. like in monuments of mars, this functions both as a way to compensate the player for taking the time to explore a dead-end path, and as a signal that the larger goal is in a different direction.)
up to this point in the game, the player hasn’t had to rely on one of protagonist simon belmont’s primary verbs: jump. the jump’s been available, but the game hasn’t forced the player to use it yet: the first segment of the game focuses on the reach and uses of simon’s whip, and while it includes some vertical navigation the jump isn’t important yet. when the player is finally forced to jump, it happens in a place that emphasizes the importance of jumping. see: to reach the first two deadly pits in the game, the player must actually travel downwards to a screen below the plane she started at. and the basement, as an environment, provides a clear visual context for the danger of those first jumps: an underwater lake is visible at the bottom of the screen.
also note all the things the background columns accomplish: they’re providing visual cohesion with the area above, they’re breaking up the area horizontally, drawing attention to the pits, and they’re showing clear boundaries of where all the platforms end. there are far more difficult jumps later in the game; the designers have clearly tried to emphasize the importance of the player’s first pit jump.
when the player completes the jumps and ascends from the basement she gets to stand on top of the wall that was previously an obstacle: as with nifflas’s underwater adventure, there’s closure there. this is a complete story. more importantly, it gives this level a story and a shape. that’s (one of the reasons) why this section of this level recurs in so many other castlevania games (bloodlines and chi no rondo, for example): it’s memorable because of its shape.
what’s more, it tells us something about the larger story of castlevania. this is architecture. it tells us that this isn’t just a series of hallways, it’s a castle, with floors stacked above and below one another, with staircases leading us through structures that are more complicated than the left-to-right of an outdoor setting. a straight left-right might make sense in an open field, but this is a castle, and its ancient corridors wind in every direction. it also makes sense to the character of simon belmont, whose strong horizontal attack means his greatest challenge comes from navigating vertical terrain.
 i think that the palette of seven unlabelled layers makes the editor more confusing than it needs to be.
 the other big reason is lack of creativity.