Critique of Crystal Cave
I had the chance this week to play through an educational game called Crystal Cave. It was designed and implemented by The Yard Games at the University of Wisconsin-Madison. Its general purpose is to teach students about how crystals are formed and what their molecular structure looks like.
Learning Goals
The primary objective of Crystal Cave is to teach players about how crystals are structured. The intended audience seems to be younger students, perhaps in late elementary school and middle school. More specifically, the goal of this game appears to be to increase learners’ understanding of how crystals are structured and how the different elements of a crystal’s molecular makeup change the crystal. The game has players explore the different patterns by which a crystal could be structured with different types and shapes of molecules, different charges on those molecules, and how defects or obstacles play a role. Each level gets slightly more complex in how many factors must be taken into account when building the crystal. For example, one of the later levels has a relatively simple starting molecule structure, but the distribution of charges presents a challenge. Moving further through the game, one of the levels even has an obstacle, a spot where a molecule cannot be placed, to demonstrate how defects in crystals come about and affect the overall structure.
While this game is meant to be introductory, there are a few pieces of essential prerequisite knowledge. First and foremost, players need to have well-developed spatial awareness and visual perceptual skills. The overall structure of gameplay is similar to that of Tangrams, where players place shapes in a fixed grid. In order to be successful in this game, players must be able to reason about the ideal ways in which to place each molecule to fill the board. Second, players should know the basics of what a molecule is and how molecules come together to form everything around us. Without this context of molecules as the building blocks of our world, it will be extremely tough to connect the challenges of the game to any new information about crystals. Lastly, most of the levels use crystal molecules that have different charges. These charges are explained in relation to magnetism, so learners must be familiar with the basics of magnetic repulsion and attraction, as well as the idea that positive and negative things must balance each other out.
After playing Crystal Cave, we might see transfer for learners in their science classes with a greater understanding of how crystals are formed and what their structure looks like. One pushback I have on this, however, is that the levels of the game are strictly 2-dimensional while crystals are very much 3-dimensional objects. The game does not mention or reference this difference and I would imagine that this may lead to students’ misconceptions about how 3-dimensional crystals are formed. I wonder if this game would do better as a physical game so that learners could explore how the molecules fit together along the “z-axis” as well.
Game Elements
The core loop of Crystal Cave is each level. Players are given a certain molecule to work with and a grid, the task is to lay the molecules out on the grid to maximize coverage and stability. At a micro loop level, players must decide where is the best place to put a molecule next, watching out for balancing charges for charged molecules and avoiding any defect obstacles if that level has them. Additionally, some levels start with a sort of comic strip introduction. This is one of the primary vehicles used to deliver educational content as concepts about crystal structure are explained with these comics. As for macro loops, there is a broader mechanic of star collection. At each level, players can earn up to three stars based on how successful they were at maximizing coverage and stability; future levels are unlocked when players collect a certain amount of stars.
Crystal Cave’s nouns are the molecules that are being placed and any obstacles that are in the way. As for the verbs, players can drag molecules to place them or rotate them, and submit their final structure to “grow” the crystal. Once players grow their crystal, we see a zoomed-out version of the structure created, with the pattern repeating several times across the screen. Once again, I feel that there is a missed opportunity here to augment that animation to add understanding of the 3-dimensional nature of crystals. For example, the pattern could first zoom out as it does, and then maybe it could grow along the “z-axis” as well to form a full crystal. A nod to the third dimension would really improve the potential for transfer of Crystal Cave, and the level conclusion is an interesting place to implement this.
Learning Mechanisms
Crystal Cave is definitely geared toward induction and refinement. It specifically uses activating preconceptions as its core learning mechanism. As mentioned earlier, the levels that use new concepts for the first time have a comic strip at the beginning to explain them. For example, when the game introduced the concept that crystal molecules have positive and negative charges, the comic explained this in relation to magnetic charge, something learners were probably already familiar with.
This approach is really interesting for a number of reasons. First, the activation of preconceptions is well done in my opinion, especially since it relies more on a common life experience than the actual science behind the experience. In the magnetism example, the content is accessible both for learners who understand magnetism, but also for learners who have played with magnets before and have experienced repulsion first-hand. Secondly, the use of a character inside the actual comic who is learning these concepts is a cool decision. This character verbalizes some of the assumptions that the players might have such as “so crystal molecules just have to fill up the space? Easy Peasy!”. I imagine that being able to relate to a character in the comic and to be able to see that other learners are confused, struggle with the concept, or are at the same level as a learner could be empowering and help boost confidence. However, the big problem with this comic is that it is entirely skippable. For players that just want to get to the level’s puzzle, they are able to brush past the comic, forgoing all of the important learning and confidence-building that is available.
When it comes to the core game mechanic, a key learning mechanism was variability. After a level introduced a new concept, the structure of the molecule players had to use to grow the crystal changed in complexity. This added a variation through which players could continue to practice the concepts they learned in previous levels. For example, the first level that uses charged molecules has them in an I-shape structure. From there, players move to the next level that uses L-shape molecules, adding to the complexity and challenge while leaving room to practice the same concepts.
Overall Takeaways
Crystal Cave was an interesting approach to teaching about crystals, and I had fun playing it. The mechanic of building the crystals was interesting. Through experimentation, learners can understand the qualities of the molecular makeup of crystals that increase strength and stability such as repeating patterns, balancing charges, and avoiding leaving gaps. And with variability, learners practice one of the core concepts regarding crystals while exploring further how to build a strong structure with different molecules. Further, the comic strip mechanism at the beginning of some levels uses activating preconceptions to drive understanding of key characteristics of the growth of crystals. However, the “skipability” of the comic strip leaves room for improvement in this game. My main criticism of this game is that the essential educational content is sort of unattached to the core loop and core game mechanics. Students who arrive at this game already engaged in the subject can learn a lot about crystal structure. But for students who are less interested in the subject, to begin with, they might be more likely to skip the comic and would be able to play and learn more about spatial reasoning than crystals. So to sum up, I think that Crystal Cave is a moderately successful educational game. Their learning objective of teaching players about the structure of crystals is on its way to being accomplished, but I would advise that they connect the comic mechanism to the game a bit more directly in future iterations.