['Homer in Silicon' is a biweekly GameSetWatch-exclusive column by Emily Short. It looks at storytelling and narrative in games of all flavors, including the casual, indie, and obscurely hobbyist. This week she looks at Cellcraft, an indie RTS developed to teach cellular biology to middle-school children.]

Cellcraft is a Flash-based RTS about cellular biology, from Super Energy Apocalypse author Lars Doucet.

Like his earlier work, it's a science-heavy look at a complex system, but where Super Energy Apocalypse is looking to model and persuade, Cellcraft is more about teaching: getting players familiar with how the organelles of a cell work, what they're for, and what might threaten their survival. Gameplay consists of gathering resources such as glucose and amino acids, ordering organelles to produce energy and defenses for the cell, and fighting off waves of viruses.

I thoroughly approve of this idea. To this day, my default picture of the organs in a human body is based on the Visible Man Kit my mother helped me paint when I was little, rather than any diagram in a textbook: the spatial manipulation was much more effective at getting the details into my brain.

Video game presentations can take that a step further, not only offering manipulable spatial treatments but also a demonstration of how something works systematically. A series of challenges based on understanding and manipulating a cellular system is far more effective for most students than a multiple-choice test asking for the definition of a lysosome.

Some of this has to do with learning styles, because some students remember visual representations better than textual ones, but a lot of the benefit comes from the active learning format.

In this context, story and gameplay aren't present simply to support one another. Both are directed at a third goal: teaching. The gameplay all takes place on the level of the cell, so the story cut-scenes have to carry the weight of explaining what is happening at the large scale. Why is the cell being given light, or subjected to cold? What is the purpose behind building up a cell in pieces?

Doucet writes: "The game is aimed at a wide audience, but is designed to include middle school-aged children on the youngest end. We did our best to come up with a story that justifies building up a cell piece by piece (to introduce the player to new features gradually) and then putting them through a series of sadistic tests (ie, level progression)."

...and I think they did a fine job with this. The story silly on the face of it -- some intelligent duckbilled platypus aliens are threatened with extinction, so they engineer a cell to carry some of their DNA to earth, where it will reconstruct the platypus from components. As the cell is being developed, it has to be trained to fight off viruses, too, which provides an explanation for the frequent invasions.

This narrative raises a lot of incidental questions if you think about the emotional aspect: how are they so calm about the imminent destruction of their culture? To what extent will the reconstructed platypus count as a "continuation" of their species?

But the cheery graphics and music, and the lighthearted dialogue, discourage the player from dwelling too much on that kind of topic. What we're left with is an amusing story that sketches in a broader context that the gameplay cannot.

I am aware that some people are concerned about what they see as a creationist stance in the story, a concern reinforced by the choice of science advisors for the game. I can't speak to the latter point. What I can say is that I don't think "duckbilled platypuses added organelles to this cell gradually" is code for an intelligent design agenda. It's silly enough that I don't imagine most kids will confuse this story with an actual explanation for the origins of life. (Children are less easily led and less foolish than adults tend to give them credit for.)

The story does provide memory hooks for recalling the game content: for instance, I might be more likely to remember the level about mitochondria using glucose to produce heat because of the surrounding narrative about accidentally crashing on a cold asteroid.

I do have some gripes about the design. The interface is probably the biggest one. There's no level of zoom at which you have enough information, so you're constantly adjusting the camera in and out. The game tries to help by moving the zoom out when new viruses are coming in, but that's only sometimes useful, and there are a huge number of other occasions where I needed to adjust what I could see.

Organelles can take damage, but you can't see exactly what the damage level is unless you click on the organelle in question, unless it gets sickly enough for the graphics to show that organelle shriveled up and dying -- at which point it's already lost a large proportion of its effectiveness.

In addition, organelle functions have a complicated cost -- so much adenosine triphosphate, so many amino acids, so much fatty acid, and so on. The cost breakdown is shown on the opposite part of the screen from where your own resources are listed, and so you have to keep looking back and forth to compare in order to find out whether you can afford the purchase you're contemplating. It would be tidier if the cost numbers showed different colors to show what you can and can't afford -- so the amino acid cost would turn red, say, if you didn't have enough AA lying around.

The level design is also imperfect. There's a long, chatty tutorial during which you can't do much except follow the tutorial instructions precisely, followed by a steep plunge into much more challenging play.

I would have preferred to have longer playable levels during the tutorial. I wanted a chance to really get used to the organelle functions I was supposed to be learning and build a sense of strategy on the small scale (hey, it's a good idea to have a bunch of slicer enzymes lined up well before the virus show up on the scene!) before being asked to use the system in a more complicated context.

There's one level where our robot tormentor says that he's going to turn the glucose feeder back on, but I never found any glucose lying around. It would have been useful, because the light levels in that round fall to around 20% of normal, severely cutting back how much glucose I could produce with chloroplasts alone.

Since this is also a level that appears shortly after the end of the tutorial portion, I wasn't even sure whether I was doing something wrong. I died over and over, my cell exploding pathetically and its organelles turning black. It took me quite a while to realize that even though I was having problems with glucose supply, I should produce one fewer chloroplast and one more mitochondrion at the beginning of that stage. So it was solvable, but I was hit with too much complexity too soon.

Things get quite a bit better after that point, as the level design starts to be more about providing interesting variations. I was pleased to reach a point where the invasion of the viruses was actually useful, because I needed the fatty acids they could provide.

In these later levels, the challenge continues to ramp up, but a bit more evenly than in the initial jump from tutorial to virus invasion. To me, this portion of the game was by far the most instructive. Struggle with your build order long enough and you'll not only remember which organelles produce what, you'll have a visceral sense for the resilience of a cell. Up to a point, you can pretty reliably repair yourself, if you have enough glucose and amino acids to draw on. After that, it's an ugly downhill spiral to necrosis.

Overall, Cellcraft is at its best as an educational game when it doesn't stint on the game-y-ness.

[Emily Short is an interactive fiction author and part of the team behind Inform 7, a language for IF creation. She also maintains a blog on interactive fiction and related topics. She also contracts for story and design work with game developers from time to time, and will disclose conflicts with story subjects if any exist. She can be reached at emshort AT mindspring DOT com.]