MainFrames is a side-scrolling puzzle platformer that makes the unique choice to set itself in a 1990s-style desktop computer interface. I play as Floppy, a desktop icon shaped like a 3.5″ floppy disk with arms, legs, and beady eyes who appears one day inside a computer network. A helpful figure in the form of a penguin informs Floppy that their icon is not linked to any program, and they will have to travel through all eight of the network’s computers in succession to find their admin and their true purpose. As I help Floppy navigate across the windows, icons, and applications of each networked computer, I witness the remnants of a programming team and their work on a mysterious MainFrames project inscribed into the backgrounds of each level.

I am not a computer savvy person. Even though I spend most of my daily professional life interacting with a computer, write for and post to this website using a computer, and spend as much of my free time as I can manage playing videogames programmed by a computer, I have almost no understanding of the software that makes these machines work. This means the biggest challenge for me in MainFrames is comprehending the characters and concepts Floppy encounters inside the computer network.

I’m not totally uninformed. I recognize some of these figures. Floppy is the most obvious, a 3.5″ floppy disk being the classic icon for saving a file to a desktop. The helpful penguin is reminiscent of the penguin mascot for the Linux operating system. The computer cursors, desktop windows, and blue crash screens that make up the platforms and objects in MainFrames’ levels are all familiar sights to me.

Then new characters appear. They are black squares with simple faces on long, slender legs. These figures call Floppy a daemon, and apparently they are daemons as well. Everything I know about folklore suggests that daemons are evil creatures which must be banished for a world’s survival. But these daemons are not malicious. They have formed a haven between the networked computers where they can rest from their functions, a digital break room cluttered with jpegs of pixelated shelves, chairs, and childish drawings scrawled on the walls.

All of this is over my head. I do not know if all this talk of daemons and break rooms is reimagining computer functions as characters and locations inside a narrative or if everything being discussed is literally happening on a programming level. One daemon explains to Floppy that they were “created to run programs while remaining hidden from users.” Instead of elaborating, they send Floppy away via elevator to the next computer in the network to continue their own personal mission for self-identification. I do not know if this is an accurate description of a computer daemon or an embellishment to give these characters purpose within the narrative. If I’m totally honest, I come out the other end of MainFrames’ narrative having no real idea what the heck just happened.

Despite my shocking ignorance of how computers work, I have little difficulty understanding MainFrames’ platforming puzzles. Since they take place on a computer desktop, an aid that helps neophytes like me visualize a computer’s functions as a series of files stored in folders on the surface of a desk, everything I see is immediately familiar to me.

Level geography begins simply to ease me into MainFrames’ conceit. The first screen is backdropped by a typical desktop wallpaper depicting a hill with a dirt road flanked by colorful flowers. Floppy stands in a window sitting on top of this background, a thick black line beneath their feet providing firm ground for them to stand upon. Additional windows stretch off to the right, each containing more platforms. I prompt Floppy to run to the right and jump between each platform; it is effortless, as the player character is swift and responsive to my inputs.

This first room teaches me the concepts I need to understand MainFrames’ level design. Windows support the spaces where platforms may appear, but they are not platforms themselves. Floppy may jump between windows, but if a window does not contain a platform, or they miss, then they will fall to the bottom of the desktop, suffer whatever counts as “death” in this setting, then reappear back in the screen’s first window. Respawns are infinite and nearly instantaneous which makes the many, many deaths Floppy will encounter over the coming hours of platforming and puzzle solving much easier to endure.

The passage between screens is recognizable as an angry static cloud on the edge of a window, transporting Floppy straight to the next screen when they touch its surface. These following screens introduce more basic platforming concepts. If Floppy encounters a vertical platform, they may wall jump off its surface. If the jump button is pressed again while Floppy is mid-jump, they perform a flip that impossibly carries them a small distance horizontally. These familiar platforming concepts carry Floppy all the way from the beginning to the end of their adventure through MainFrames’ servers.

Soon after these bedrock concepts are introduced, Floppy encounters a cursor embedded in the floor of a platform like a sword driven into a stone. This is the tool that makes MainFrames unique as a puzzle platformer. After Floppy tugs the cursor free, it becomes a secondary pseudo-player character of which I am allowed limited control. For this first screen, the cursor may only do one thing: Click and drag the window Floppy stands in to the other side of the screen, letting them reach the exit and access the next area.

Subsequent screens ease me into more of the cursor’s functions. A screen contains two windows, one empty and one containing a platform. I can cycle the cursor between the two windows using the controller’s shoulder buttons, moving the empty window out of the way so Floppy may use the second window’s platform to reach the exit. The ability to move entire sections of level geography feels powerful, perhaps too much so. I am soon confronted with its limitations. Not every window may be manipulated. Many screens across the eight servers do not use the cursor at all, forcing me to rely on pure platforming skill to guide Floppy to safety.

These mechanics are the basics which recur across all eight MainFrames servers. Each one Floppy visits also has its own unique twist to keep the platforming fresh, growing in complexity and difficulty as they near the finish line.

The first server Floppy travels to after meeting their fellow daemons introduces new desktop icons. When I press the jump button while Floppy jumps over them, he bounces off them and keeps his momentum going through the air. Many screens have chains of these icons which Floppy must cavort expertly between to reach the exit. Curiously, and perhaps counterintuitively, the cursor never interacts with these icons. Jumping on them with Floppy is the only purpose they serve.

The unique properties of different icons further complicate the platforming. BUMP.sh icons alter Floppy’s momentum when struck, launching them in a direction marked by an arrowhead on a blue diamond. GEAR_BUMP.ex icons change the direction that every BUMP.sh icon points to when they are struck, potentially sending Floppy in a different direction than they need to go when they reach the next icon in a chain. The first time I am forced to really stop and examine one of MainFrames’ platforming challenges is a screen filled with GEAR_BUMP.ex and BUMP.sh icons. After a moment determining the proper order in which to strike them, I find a path that leads Floppy to the exit and on to still more difficult challenges.

Later servers add even more intricate new mechanics. Windows appear that grow when Floppy moves and shrink when they stand still, forcing them to find enough running space to fully expand the screen’s windows. Corrupted windows filled with garbage data will not hold Floppy’s weight, though highlighting them with the cursor turns them into an error screen that will. This creates an obstacle that challenges my timing and button pressing aptitude when there are multiple corrupted windows and only one cursor to highlight them all. By the time Floppy reaches the final server, screens are filled with so many interactable objects and deadly obstacles that nearly every one takes at least a moment’s consideration and several retries before it may be finished. MainFrames’ platforming mechanics do a wonderful job combining precision and puzzle solving.

Not everything found inside a server is part of a puzzle-platforming conundrum. Floppy encounters crude visualizations of objects like an espresso machine, a portable cassette player, and a railroad handcar attached to hydraulic pumps. Some of these may be interacted with. Others seem to be purely decorative. A weather-predicting machine that operates off a 50:50 random number generator mystifies me for several minutes. I finally drag Floppy away from it when I can find no impact on the level from interacting with it. I presume these objects have some use on platforms that support achievements. On the Switch version of MainFrames I play, they are only decorative time wasters.

While Floppy overcomes the eight servers’ various platforming challenges, I bear witness in the backgrounds of many screens to the remnants of the MainFrames programming team and their mysterious project. My introduction to the team comes in the form of a pixelated, black-and-white photograph that dominates most of one screen: A racially diverse group of men and women gathered around a table artfully framed between Macintosh 128K computers. A short time later, I see notes from the team arguing that someone named Jim should be included in MainFrames’ credits, even if he no longer works with the team. The next screen contains a photograph revealing Jim is a cocker spaniel who passed away. These early, light-hearted additions do the important work of ensuring I see the team as people first before I become embroiled in the mystery of the MainFrames project.

What this team of computer programmers were trying to create is not clear to me. New messages between its members provide some vague information but few concrete details. My interrogation of these facts is interrupted by corporate intrigue halting the team’s work, disrupting my understanding of what MainFrames was meant to do as abruptly as the team’s work. Am I meant to understand that MainFrames is the very videogame I am now playing? If so, how am I playing it if it went unfinished and unreleased? The narrative’s progression and conclusion is unclear.

It is possible that I am reading too much into this mystery. It is possible that the actual function of MainFrames is left deliberately unanswered and I am drawing importance from insignificant background details. It is also possible that this real answer is hidden behind MainFrames true ending which becomes available when Floppy reaches the end of the eighth server with every collectable from every screen in their digital pockets.

All of these collectables come in the form of other computer daemons, the square-shaped figures on slender legs Floppy encounters in the break room. The vast majority of these are found as tiny figures that scuttle around the borders of windows like ants. If Floppy can perform a flip while touching one, then they step through a doorway and reappear at the top of the screen to watch their savior’s progress through the remainder of the server. By the time Floppy reaches the end of the server, they have an entire flock of tiny daemons spectating on their adventure.

A smaller but more significant number of daemons are earned for completing MainFrames’ most difficult platforming puzzles. Many screens, instead of having exits to a new screen, will be dead ends where Floppy will find a full-sized daemon stranded in a window. To add this daemon to their collection, they must help it to reach an elevator on the far side of the screen. These daemons are vulnerable to all of the same hazards that send Floppy respawning back to a screen’s starting window. They also move when Floppy moves, essentially forcing me to control two player characters at once with a single directional pad.

Helping these daemons reach the exit elevator is made more difficult than it first seems because they do not move like Floppy. One variety jumps much higher and farther. Another moves much faster and follows a unique trajectory marked in the screen’s background. A third can stick to window edges, walking with perfect confidence on their sides and even their bottoms. Finding the specific way to steer these daemons across a treacherous screen is the puzzle.

Finding every daemon to earn MainFrames’ true ending isn’t easy. I see no indicators on the interface that Floppy has found every daemon in an area and may move forward. Some screens will suddenly restrict Floppy from backtracking, arbitrarily blocking them from claiming any missed daemons. There is no option to revisit completed servers (though a developer post on MainFrames’ Steam community page says they are working on it). MainFrames isn’t that long—it takes me about three hours to finish from a fresh save file to the credit roll—so a mandatory replay to find a few missed daemons isn’t too daunting. Still, I feel that I should not be required to replay the entire campaign to get the ending that doesn’t anticlimactically consign Floppy and the other daemons to oblivion.

My inability to comprehend the vocabulary and themes MainFrames employes in its narrative does little to hinder my enjoyment of its platforming design. It performs an admirable double trick as a challenging, skill-based platformer and a thoughtful puzzler. The barriers put in place to get its true ending is my biggest complaint. Since I’m not playing for the story in the first place, this does little to bother me. MainFrames is a wonderful way to challenge my fingers and exercise my brain.