Game Design
The five UX principles that shaped every design decision in MyRin - from touch targets to difficulty pacing to the deliberate absence of timers.
Every design decision in MyRin is the result of a principle, not a preference. Some of those principles are widely shared in mobile game design; others are specific to what we were trying to build. Here are the five that shaped the decisions that mattered most.
The minimum recommended touch target size for mobile is 44x44 points (Apple's HIG) or 48x48dp (Google's Material Design). These are minimums for accessibility; the ideal for a game played one-handed on a phone in motion is larger.
MyRin's grid cells are sized to be comfortably tappable with the pad of a thumb, not just the tip. We tested multiple grid configurations - smaller cells allowed more complex puzzles on a single screen, but tap accuracy on smaller cells created frustration that was indistinguishable from puzzle difficulty. Users were making errors because of imprecise tap registration, not because they were stuck on the puzzle logic. We widened the cells.
The result was puzzles that had to work within a tighter grid constraint, which turned out to be a design advantage - the constraint pushed us toward cleaner, more focused puzzle configurations rather than complex grids that felt visually noisy on a phone screen.
Time pressure is one of the most common mechanics in mobile puzzle games because it is an easy difficulty lever: the same puzzle that is comfortable at 60 seconds becomes genuinely challenging at 30 seconds. It also produces the kind of completion anxiety that drives re-engagement - users feel they "almost made it" and try again.
We deliberately did not add timers to MyRin, and the decision was controversial in early playtesting. Some players wanted the pressure. Our reasoning: timers change the cognitive skill being trained. A timed puzzle tests processing speed and reaction. An untimed puzzle tests reasoning. We are building a reasoning training game, not a reaction game. Adding timers would have made the product more engaging by some metrics while making it less effective at its stated purpose.
The users who benefit most from MyRin are exactly the users who would be most likely to quit a timed version: people who think carefully and methodically rather than quickly. Building for those users required resisting a mechanic that would have made the game more broadly appealing but would have excluded the audience it was designed for.
Every MyRin puzzle is logically solvable to a single correct answer. No puzzle requires a guess. No puzzle has multiple valid solutions. This is a hard design constraint that eliminated roughly 30% of our early puzzle designs in development.
The reason for the constraint is trust. A puzzle game where players cannot be certain that their reasoning is sufficient - where sometimes the right approach is to guess and check - trains a different relationship with problems than a game where every puzzle yields to systematic reasoning. Players who trust that every puzzle is solvable persist through difficulty. Players who suspect some puzzles might require guessing give up earlier because guessing is not satisfying when you know you are guessing.
Enforcing uniqueness also forced higher-quality puzzle design. It is easy to create a puzzle with multiple valid solutions; it takes significant additional work to ensure that the logical constraints eliminate all but one. That additional work produced better puzzles.
Mobile app retention follows a specific curve: the drop between first session and second session is the largest drop in the retention curve. Users who complete a second session are significantly more likely to return for a third; users who do not complete a second session rarely do.
This means that the first session must do two things simultaneously: introduce the puzzle mechanics well enough that new players can experience success, and introduce enough of the game's depth that experienced puzzle players feel genuine engagement rather than condescension.
MyRin's first 10 levels are calibrated for this dual requirement. They are simple enough that a first-time logic puzzle player can succeed without prior experience. They are varied enough that an experienced player can see the breadth of what the game will offer. And the final two levels of the opening sequence are meaningfully harder than the first eight - providing a taste of the difficulty that the rest of the game delivers, without front-loading frustration.
We playtested these 10 levels more than any others. The version that shipped was the twelfth iteration of the opening sequence. The retention curve after the first session improved measurably with each major revision.
MyRin's visual design is deliberately minimal. The grid is clean. The color palette is restrained. Animations are functional rather than decorative - they confirm a correct action or highlight an incorrect one, rather than celebrating every interaction with particle effects and screen flashes.
The reasoning is cognitive load management. Players solving a logic puzzle are using working memory and executive function intensively. Visual complexity - decorative animations, rich textures, multiple simultaneous visual events - competes for the attentional resources that the puzzle itself needs. A cluttered visual environment makes hard puzzles feel harder by the wrong mechanism: visual overwhelm rather than logical challenge.
Every element in MyRin's UI exists because it communicates something the player needs to know. Elements that do not communicate necessary information were removed, including several decorative elements from early design iterations that testers described as "distracting" during difficult puzzles. When something is described as distracting during the hardest cognitive task the app offers, it comes out.
These principles occasionally conflict. The no-timers principle reduces engagement metrics that correlate with retention. The single-solution constraint limits puzzle variety. Minimal visual design conflicts with the "polished" expectation that many App Store users have from highly-funded games.
Resolving these tensions required clarity about what MyRin is optimizing for: cognitive training effectiveness and respect for the player's intelligence. Every design decision that conflicted with those priorities lost, regardless of what the engagement metrics preferred. The resulting product is more narrowly excellent than broadly appealing - but it earns a different kind of loyalty from the players it is actually designed for.