Critique Blog — Post 2

Game | Crystal Cave

Game Metadata

Game Name: Crystal Cave

Designer/Developer: Field Day Lab

Platform: Online game, browser-based

High-level Instructional Goal:

To teach students in grades 5–8 how crystals form at the molecular level, to make crystal structures from atoms.

Link to the game:

Learning Objectives

Crystal Cave teaches players how to make ordered and stable crystal structures by arranging molecules of different shapes and properties. The game lets students explore and deepen their understanding of molecular stability, ionic charges, crystal defects, and spatial patterning. For example, it teaches students that crystals are formed from tightly ordered molecules that occur in nature, and neutralized molecular charges (+ and -) increase stability.

The game requires some prior knowledge of the language the game uses, such as molecules and charges. Also, it assumes players know how to work with the interface. For example, use their mouse to drag a virtual crystal molecule and place it into the given grid.

Drag and place a molecule

Game Elements

Gameplay Loop:

In Crystal Cave, players are tasked with 9 game levels. Each level starts with a storyboard-style tutorial that walks players through some domain knowledge about crystal structure. The goal is to stack a specific type of crystal molecule in a given grid for each level, such as a 6x6 grid. Players can see scores and stars representing crystal stability as they play the game. After clicking the “Grow Crystal” button, players get an instant summary of the score for that game level. Also, players can learn the type of crystal with the molecule configuration they just made, and save the corresponding crystal in Crystal Museum, which allows them to revisit it later.

Storyboard-style tutorial


crystal molecules, grid, crystal stability score, score summary, crystal museum


select a level, drag and place a molecule, rotate molecules, clear grid, back to menu, check crystal museum

Player experience:

When first playing Crystal Cave, I felt the tutorials did an excellent job in providing necessary domain knowledge about crystal structure that players can leverage to complete the following task. From level 1 to level 9, players are tasked with arranging molecules of more complex shapes and properties. To unlock a new level, players need to get a minimum number of stars.

Unlock a new level with a minimum number of stars

From my experience, I found it hard to achieve 3 stars in level 4. The prompt asks players to “try different patterns to get 3 stars”. After having tried more than 10 times, I could only get one star. I began feeling frustrated because I didn’t know how to make an ordered and stable configuration, but there was no way to get a hint. I gave up playing level 4.

I had difficulties in completing level 4

In Crystal Museum, players can see the types of crystals they have collected. I expected to see more details about each kind after clicking on crystals, but nothing happened.

Crystal Museum

The game is simple to learn but has depth to the exploration process. The puzzle-like molecule placement is very satisfying when you finally get that perfect configuration, but can be disappointing if you can’t figure out a way to get 3 stars after multiple trials.

Learning Mechanisms


Crystal Cave structures learning content modularly in 9 levels. It teaches a player to stack together molecules into a pattern in level 1 and then practice with molecules in more complex shapes in levels 2 & 3. The game introduces molecular charges in level 4. The principle of scaffolding enables players to learn bite-sized knowledge in a sequence, and build knowledge towards completing more complex tasks later.

Neutralized molecular charges (+ and -) increase stability


After players complete level 3, the game prompts them with two single-choice questions. These questions are designed to test their understanding of crystal molecule structure and structure stability, and summarize the learning materials. Quizzing re-exposes players to core concepts that they just learned.

Question after level 3
Reiteration of the core concept

Immediate Feedback Timing

According to rules in molecular charges, if the same poles are put next to each other, they push apart. If players put the same poles together in the gameplay, they will see the molecule’s animation indicating two poles repel each other. Also, white atoms turn black, and the crystal stability score decreases. These visual cues inform that players should adjust the current molecule configuration to be more stable.

Provide immediate feedback on errors

Overall Critique

I think Crystal Cave succeeds in creating an engaging learning experience where players can learn geometric arrangement, molecular charges, and molecular stability in crystals. The quiz questions encourage players to recall material they just learned in gameplay.

However, some students might have difficulties completing certain levels, such as level 4, as I encountered. The game falls short in not providing guidance/clues for those who need help, leading to players quitting the game without coming back. Game designers could create a more significant learning experience by providing detailed information about crystals that students collect after completing each game level.



Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store