Design Lenses

Design lens review

A lens is a viewpoint plus questions, not a rule (Schell). This skill runs a battery of lenses against a game and outputs findings an agent can implement. The defining failure of prompt-built games: mechanically correct, sensorially and emotionally dead. The lenses find where.

Procedure

1. Play first, cold. Load like a first-time visitor. Record: time to first input, time to first win/lose feedback, what you understood without instructions, where you got bored. Play twice — once naive, once trying to break it (spam inputs, resize, lose on purpose, idle).
2. Write the MDA sentence: "This game wants the player to feel X via dynamic Y produced by mechanics Z." Can't write it? That's finding #1 — no essential experience. Then write the loop contract: "player does [verb] to achieve [objective] while [pressure] creates risk; success → [reward], failure → [cost/retry]". Any bracket you can't fill is a finding too.
3. Run the rejection gates (below). Each failed gate is an automatic blocker — no lens needed.
4. Pick 8–12 lenses. Always: Essential Experience, Fun, Feedback, Juiciness, Accessibility. Add by genre (Skill vs Chance for arcade, Curiosity for puzzle, the Toy for sandbox/physics).
5. Answer with evidence — a timestamp, a code path, a missing sound — never vibes.
6. Severity: blocker (player quits or never understands), major (understood but flat), minor (polish), idea (opportunity).
7. Findings as lens → evidence → fix, fixes concrete ("80ms hit-stop + 4px shake on collision", not "juicier"). Order: blockers, then cheapest major wins (audio + shake + score popups = highest fun-per-line).
8. Re-play after fixes, re-asking only the failed lenses and gates.

Rejection gates

Binary go/no-go tests, self-applied in active play before claiming a game is fun. Any "true" = automatic blocker; fix or iterate before polishing:

• The first 30 seconds lack a real decision.
• The player can ignore the main mechanic and still progress.
• The objective is unclear without reading source code or instructions.
• Failure arrives before the player can understand why.
• Challenge is only "more things", never better combinations.
• Rewards change nothing — not strategy, score, progression, or feel.
• The space is decorative and shapes no decisions.
• The game is fun only in the designer's explanation, not in active play.

The lens battery

(All lenses Schell unless noted; questions paraphrased. "Smell" = the browser-game failure mode.)

Experience

• Essential Experience — what experience should this create; does every system serve it? Smell: a feature list, not a game about something.
• Emotion — what should the player feel; what's the arc of a 60s session? Smell: second 10 feels identical to second 100; death has no sting.
• Fun — which parts are fun in themselves? Is failure fun? Smell: the core verb is a chore — in a 2-minute game the verb IS the game.
• Surprise — what subverts expectation; rare events, escalation beats? Smell: run two has seen 100% of the content.
• Curiosity — what questions live in the player's mind ("what's at 100 points?")? Smell: nothing teased, no visible next milestone.
• The Toy — strip the goals: is it fun to merely fiddle with? Smell: movement functional but dead; nobody would touch it without a score.
• Pleasure (pairs with MDA aesthetics) — which pleasures exist (sensation, anticipation, triumph, destruction); which genre-expected ones are missing? Smell: mono-pleasure; no audio at all is the #1 gap.

Systems & emergence (Wright — SimCity/Sims/Spore school)

• Possibility Space — would ten players produce ten different outcomes, or is this a corridor wearing a game's clothes? Smell: every run identical by design, not just by lack of content.
• Story Generator — can a player recount a session story the designer never wrote? Systems should manufacture anecdotes. Smell: only authored moments are memorable.
• Indirect Control — is the player a gardener (shaping conditions, the system answers back) or a typist (commanding outcomes directly)? Smell: total control, zero surprise — data entry with a skin.
• Compression — does every simulated variable change a decision the player actually makes? A sim is a caricature: model what generates choices, fake or cut the rest. Smell: simulation detail nobody's choices touch.
• Investment — has the player made/named/shaped something they'd be sad to lose, and is it then put at risk? Creative investment manufactures stakes for free. Smell: nothing on screen is "theirs".

Mechanics & structure

• Elemental Tetrad — mechanics, story/theme, aesthetics, tech: each pulling weight, in harmony? Smell: solid mechanics in placeholder art, or gorgeous art over a hollow loop.
• Unification — what's the theme; what fights it? Smell: prompt-collage — pirate ship, neon UI, fantasy SFX, sci-fi enemies.
• Problem Solving — what problems does play pose; do new ones generate each run? Smell: optimal strategy found in 30s, never changes.
• Goals — concrete, achievable, layered (next 5s / session / meta)? Smell: "now what?" at spawn; one flat goal.
• Meaningful Choices — do choices matter; any dominant strategy? Smell: three weapons, one strictly best; upgrades the player can't perceive.
• Simplicity/Complexity — emergent complexity from simple rules, or rulebook bloat? Smell: six mechanics used once each. One verb deep beats five shallow.

Balance & challenge

• Flow (after Csikszentmihalyi) — does challenge track growing skill? Smell: difficulty is a constant, not a function of time/score.
• Challenge — right for a first-timer; can experts self-select harder play? Smell: novice and expert get the identical experience.
• Skill vs Chance — does randomness create drama or injustice? Smell: off-screen spawn deaths; or zero variance, every run identical.
• Reward — varied, well-timed, perceptible the instant earned? Smell: points silently increment in a corner.
• Punishment — every failure fair and preventable; retry instant? Smell: death → 3 clicks to retry. Target one keypress, <2s.

Feedback & feel

• Feedback — for every action, what does the game say back, how fast (<100ms core verbs)? Status always glanceable? Smell: "did that work?" moments.
• Juiciness (popularized by Jonasson/Purho) — cascading feedback from minimal input; does it feel alive? Smell: linear motion, vanishing sprites, silent UI. Hand findings to game-feel.
• Visible Progress — advancement visible within a run and across runs? Smell: no localStorage best score, no end-of-run stats, no replay hook.

Accessibility & context

• Accessibility — cold player sees how to begin in seconds, no manual? Smell: wall-of-text instructions; first 5 seconds kill you while you hunt for the keys.
• The Player — who actually plays this; designed for them or the designer? Smell: twitch platformer aimed at casual link-clickers.
• The Venue — a browser tab: interruptible, sound-off default, resize, touch AND keyboard, played at work. Smell: runs while tab is blurred, audio never recovers post-gesture, breaks at non-16:9.
• Time — is session length right; natural stop/re-entry points? Smell: runs that mathematically never end, or 8-second runs with no arc.

When a human tester is available

Self-play finds structure problems; only a human finds comprehension ones. Protocol: watch live and silently — face and body language outweigh verbal feedback. Never coach, hint, or rescue: 99% of players play unsupervised, so every stumble is a design fault, not a player fault. ~5 testers per build is enough to surface the pattern; fix, then re-test with fresh eyes. Good signs are behavioral: unprompted "one more run", retelling what happened, asking "wait, what if I…".

MDA quick reference

Mechanics (authored rules) → Dynamics (runtime behavior) → Aesthetics (felt emotion). Designers build M→A; players experience A→M — review from the player's side. Eight aesthetics: Sensation, Fantasy, Narrative, Challenge, Fellowship, Discovery, Expression, Submission. Trace every aesthetic failure back to the mechanic causing it: "no tension (A) because no near-misses (D) because hitboxes too forgiving and speed never ramps (M)" — that lands as an implementable change.

Koster cross-check (A Theory of Fun): fun is pattern-learning; mastered = boring. What is the player still learning at minute 1, 3, 5? "Nothing" by minute 1 = no legs, regardless of polish.

Related skills: game-feel (implements Juiciness/Feedback findings), onboarding (implements Accessibility/Flow findings), game-balance (implements Choices/Reward findings), game-playbook (the build recipe).