gijs_pong/.planning/research/FEATURES.md

# Feature Research

**Domain:** HTML5 Arcade Pong Game
**Researched:** 2026-03-10
**Confidence:** HIGH

## Feature Landscape

### Table Stakes (Users Expect These)

Features users assume exist. Missing these = product feels incomplete.

| Feature | Why Expected | Complexity | Notes |
|---------|--------------|------------|-------|
| Basic Pong gameplay (ball + 2 paddles) | Core game loop—players can't engage without it | LOW | Ball physics, collision detection, paddle movement |
| Single-player vs AI | Standard for arcade games; gives solo players something to do | MEDIUM | AI needs configurable difficulty to feel fair |
| 2-player local multiplayer | Arcade tradition; keyboard-first implementation, same machine | LOW | Straightforward split-input handling |
| Game screens (title, mode select, game over) | Professional game expectation; unpolished without them | MEDIUM | Navigation between screens, state management |
| Settings menu | Expected in any "finished" game; customization signals quality | MEDIUM | Difficulty level, color scheme, sound toggle |
| Score tracking & display | Players need feedback on performance; missing = feels broken | LOW | HUD element, persisted in-game via canvas |
| Pause functionality | User expectation for any interactive app | LOW | Toggle game loop, overlay pause screen |
| Win conditions (first to X points/match structure) | Without clear goals, game feels aimless | LOW | Score tracking, match rounds, restart logic |
| Responsive controls (smooth paddle movement) | Core feel—sluggish controls = game feels bad | MEDIUM | Keyboard input, velocity-based movement |
| Visual feedback on collision (ball impact visual) | Players expect immediate action-response connection | LOW | Flash, particle pop, or glow on hit |

### Differentiators (Competitive Advantage)

Features that set the product apart. Not required, but valuable.

| Feature | Value Proposition | Complexity | Notes |
|---------|-------------------|------------|-------|
| Particle effects on ball impact | Creates "juice"—game feels modern and satisfying vs flat | MEDIUM | Burst of 5-10 particles, fade over ~0.2s |
| Glow/aura effects on paddles/ball | Neon/arcade aesthetic; makes visuals pop off screen | MEDIUM | Canvas shadow glow, can be toggled via settings |
| Screen shake on scoring/power-up | Physical feedback without controller; adds impact | LOW | Offset canvas camera 2-5px for 100-200ms |
| Ball trail/motion blur effect | Tracks ball movement, improves visual clarity at speed | MEDIUM | Canvas line drawing from previous positions |
| Power-ups during play (multi-ball, slow time, enlarged paddle) | Adds strategic depth, breaks up gameplay rhythm, keeps matches fresh | HIGH | Spawn logic, collision detection, timer management |
| Multiple arenas/stages (different visual themes or layouts) | Extends play value; visual freshness; progression feel | MEDIUM | Stage obstacles, different visual tiling/colors |
| Difficulty progression (ball speeds up as match progresses) | Makes game escalate tension; comebacks feel earned | LOW | Velocity scaling with score or time |
| Sound effects (paddle hit, wall hit, score, power-up) | Polished audio feedback; arcade authenticity | MEDIUM | Web Audio API or HTML5 audio elements, 4-6 SFX |
| Background music/ambience | Sets mood; modern games expected to have it | MEDIUM | Looping track, can be muted in settings |
| Combo/streak counter | Gamification hook; makes chaining successes feel rewarded | LOW | Visual counter, audio/visual feedback on streak |
| Visual variety (color schemes, neon vs retro vs modern) | Customization drives engagement; feels "yours" | LOW | Canvas color theming, easy CSS/JS swap |

### Anti-Features (Commonly Requested, Often Problematic)

Features that seem good but create problems.

| Feature | Why Requested | Why Problematic | Alternative |
|---------|---------------|-----------------|-------------|
| Online multiplayer / leaderboards | "Let players compete globally" sounds appealing | Requires backend, authentication, persistence; exponentially increases complexity; out of scope for v1 | Stick with local multiplayer; defer online until core game ships |
| Mobile touch controls | "More players via phones" seems like obvious feature expansion | Touch has different physics (no relative movement); screen size ruins UI; controls feel imprecise; derails keyboard focus | Mobile-first is a separate project; keyboard design is cleaner |
| Persistent progression / accounts | "Save player progress" feels professional | Requires database or localStorage manipulation; cheating risk; adds state management burden | No accounts for v1; each session is independent |
| Tutorial / onboarding flow | "Help new players understand mechanics" is thoughtful | Arcade games learn-by-doing; tutorial adds complexity; most Pong players understand immediately | Let players figure it out in 30 seconds; simple help text in menu |
| Ultra-complex power-up economy | "10+ power-up types for replayability" sounds great | Creates balancing nightmare; testing burden explodes; confuses simple game; dilutes impact of each power-up | Start with 3-4 power-ups; quality over quantity |
| Highly detailed obstacle-heavy arenas | "More level variety through complexity" feels deep | Clutters screen; makes collision detection harder; slows down pacing; feels chaotic vs satisfying | Simple arena variations (walls, center obstacle); minimize visual noise |
| Procedural/random stage generation | "Infinite replayability" sounds cool | Makes balance impossible; can generate unwinnable/boring states; unfair feel | Handcrafted stages; 3-5 solid arenas beats infinite bad ones |
| AI learning / adaptation | "AI that gets better as you play" | Feels unfair; players resent opponent learning from them; debugging nightmare | Simple difficulty levels; consistent, beatable AI at each level |
| Deep customization (paddle size, ball size, court dimensions) | "Let players tinker" signals flexibility | Breaks game balance; creates invalid states; players get lost in options; paralysis | Fixed geometry; color/visual customization only |

## Feature Dependencies

```
Title Screen
    └──requires──> Game Mode Select
                       ├──requires──> Solo Play (AI Opponent)
                       │                  └──requires──> Game Loop (core Pong)
                       │                                  ├──requires──> Ball Physics
                       │                                  ├──requires──> Collision Detection
                       │                                  └──requires──> AI Difficulty System
                       │
                       └──requires──> 2-Player Mode
                                          └──requires──> Game Loop (same as above)

Game Loop
    ├──requires──> Score Display
    ├──requires──> Pause Functionality
    │
    ├──enhances──> Visual Feedback (particles, glow, trails)
    ├──enhances──> Sound Effects
    │
    └──enables────> Power-ups
                       ├──requires──> Power-up Spawn System
                       └──requires──> Power-up UI (timer display)

Power-ups
    └──requires──> Game Loop (core physics must handle multi-ball, etc.)

Game Over Screen
    ├──requires──> Score Tracking
    └──requires──> Restart / Menu Navigation

Settings Menu
    ├──enhances──> AI Difficulty (toggle Easy/Medium/Hard)
    ├──enhances──> Visual Effects (toggle particles, glow, trails)
    ├──enhances──> Audio (toggle sound effects, music)
    └──enhances──> Visual Theme (color scheme selection)

Multiple Arenas
    └──requires──> Arena Selection / Mode Select Screen
                       └──enhances──> Replayability
```

### Dependency Notes

- **Game Loop requires Ball Physics and Collision Detection:** Pong is unplayable without these core mechanics.
- **AI Opponent requires Difficulty System:** Difficulty toggle is critical for fair single-player experience; easy AI vs hard AI makes massive difference in satisfaction.
- **Visual Feedback enhances Game Loop:** Particles, glow, trails don't break core game but make it feel modern. These are the "juice" that separates polished from flat.
- **Power-ups enable Strategic Play:** Power-ups require solid core loop first; launching with broken power-up balance is worse than launching without them.
- **Settings Menu enhances Multiple Features:** Settings unlock customization across difficulty, visuals, and audio without complicating core gameplay.
- **Multiple Arenas depend on Core Loop:** New arenas need stable physics first; can add in v1.x after core validates.

## MVP Definition

### Launch With (v1)

Minimum viable product — what's needed to validate the concept.

- [x] Basic Pong gameplay (ball, 2 paddles, collision detection) — Players need the core game
- [x] AI opponent with difficulty levels (Easy/Medium/Hard) — Solo players need something to do
- [x] 2-player local multiplayer — Keyboard multiplayer is arcade tradition
- [x] Score display & match structure (first to N points) — Players need goals
- [x] Title screen, mode select, game over screens — Polished feel matters
- [x] Pause functionality — Users expect to pause
- [x] Basic visual feedback (collision flash or glow) — "Juice" starts here
- [x] Basic sound effects (paddle hit, wall hit, score sound) — Arcade authenticity
- [x] Settings menu (difficulty, sound toggle, color scheme) — Control signals quality

### Add After Validation (v1.x)

Features to add once core is working and players engage.

- [ ] Particle effects on impact — Players will notice lack of visual polish; easy win for engagement
- [ ] Ball trails / motion blur — Improves clarity at high speeds; visual feedback upgrade
- [ ] Power-ups (3-4 types: multi-ball, slow time, enlarged paddle, speed boost) — Adds strategic depth after core gameplay proves solid
- [ ] 2nd & 3rd arena variations (theme/obstacle changes) — Extends play value once players want variety
- [ ] Background music loop — Ambience upgrade; audio polish
- [ ] Screen shake on scoring — Impact feedback; easy add-on

### Future Consideration (v2+)

Features to defer until product-market fit is established.

- [ ] Advanced power-ups (ice ball, split shot, shield) — Risk of over-complicating game feel
- [ ] Combo/streak counter system — Gamification; depends on user feedback about engagement
- [ ] Online leaderboards — Requires backend; out of scope for static HTML5 delivery
- [ ] AI learning / adaptation — Risk of feeling unfair; complexity not justified
- [ ] Mobile touch controls — Separate design problem; keyboard focus is cleaner
- [ ] Procedural stage generation — Risk of balance problems; handcrafted is better

## Feature Prioritization Matrix

| Feature | User Value | Implementation Cost | Priority |
|---------|------------|---------------------|----------|
| Core Pong gameplay | HIGH | MEDIUM | P1 |
| AI opponent with difficulty | HIGH | MEDIUM | P1 |
| 2-player local multiplayer | HIGH | LOW | P1 |
| Game screens (title, menu, over) | HIGH | MEDIUM | P1 |
| Score tracking & display | HIGH | LOW | P1 |
| Pause functionality | MEDIUM | LOW | P1 |
| Settings menu | MEDIUM | MEDIUM | P1 |
| Basic visual feedback (glow/flash) | HIGH | LOW | P1 |
| Basic sound effects | MEDIUM | LOW | P1 |
| Particle effects on impact | HIGH | MEDIUM | P2 |
| Ball trail / motion blur | MEDIUM | MEDIUM | P2 |
| Power-ups (multi-ball, etc.) | HIGH | HIGH | P2 |
| Multiple arenas | MEDIUM | MEDIUM | P2 |
| Background music | MEDIUM | MEDIUM | P2 |
| Screen shake on scoring | MEDIUM | LOW | P2 |
| Combo counter | LOW | LOW | P3 |
| Advanced power-up types | MEDIUM | HIGH | P3 |
| Online multiplayer | LOW | CRITICAL | P3+ |
| Mobile touch controls | LOW | HIGH | P3+ |

**Priority key:**
- P1: Must have for launch (v1) — Ship with these
- P2: Should have, add when possible (v1.x) — Polish pass
- P3: Nice to have, future consideration (v2+) — Defer or skip

## Arcade Game Design Expectations

Based on industry patterns for arcade-style games, here's what makes a Pong game feel "complete":

### Screen & Menu Flow
- **Title Screen:** Logo/game name, prominent start button, settings access
- **Mode Select:** Clear choices (Solo vs 2-Player), easy navigation
- **Game Screen:** Clean HUD (scores, timer if applicable), minimal UI noise
- **Pause Screen:** Large "PAUSED" text, resume/settings/menu options, darkened overlay
- **Game Over Screen:** Final scores, winner announcement, restart/menu navigation

### Game Feel Expectations
- Controls respond instantly (no input lag)
- Collision feedback is *immediate* (flash, sound, particle burst)
- Score changes are celebrated (sound + visual feedback)
- Difficulty scaling feels fair (AI doesn't feel cheesy at any level)
- Game is immediately playable (no tutorial; learn by doing)

### Visual Polish Indicators
- Modern Pong games use neon/glow aesthetic OR clean minimal design (rarely both)
- Movement has trails or blur at high speeds
- Impacts register visually, not just mechanically
- Color scheme is consistent (coherent visual language)

### Audio Expectations
- Paddle hits have distinct sound from wall hits (Pong classic: octave difference)
- Point scoring gets celebration audio (different from hit sounds)
- No audio ever blocks game state changes (no long audio sequences)
- Music/ambient is subtle; doesn't mask game sounds

## Competitor Feature Analysis

| Feature | Pong Quest (RPG take) | Pixel Pong Pro (arcade) | Pong Worlds (modern) | Super Pong Next Gen (our approach) |
|---------|----------------------|------------------------|----------------------|----------------------------------|
| Core Pong gameplay | Yes, wrapped in RPG progression | Yes, arcade-focused | Yes, with obstacles | Yes, with juice |
| AI difficulty levels | Multiple via level progression | Adjustable difficulty | Yes | Easy/Medium/Hard toggle |
| 2-player mode | Dungeon co-op | Local vs mode | Yes | Keyboard local only |
| Power-ups | 50+ silly power-ups | Time-slow mechanic | 5 paddle variants | 3-4 focused power-up types |
| Visual polish | Retro pixel style | Glitchy effects | Neon/modern | Glow, particles, trails |
| Sound design | Audio feedback | Arcade beeps | Music + SFX | Classic Pong tones + modern polish |
| Multiple stages | Themed dungeons | Endless arcade | 5+ worlds | 3-4 arena variations |
| Persistence | RPG progression tree | Score records | Progression unlocks | Session-based, no persistence |
| Scope | Medium (RPG wrapper) | Small (arcade focus) | Medium (cosmetics) | Small-Medium (pure arcade juice) |

**Our approach:** Skip RPG bloat, skip endless mode chaos, skip complex cosmetic systems. Instead: solid core Pong + focused polish (particles, glow, trails) + 3-4 well-designed power-ups + 3-4 arena variations. Quality over quantity.

## Sources

- [Basic Pong HTML and JavaScript Game](https://gist.github.com/straker/81b59eecf70da93af396f963596dfdc5)
- [Top HTML5 games tagged pong - itch.io](https://itch.io/games/html5/tag-pong)
- [How to Create a Ping Pong Game with HTML, CSS and JavaScript](https://www.codewithfaraz.com/content/124/how-to-create-a-ping-pong-game-with-html-css-and-javascript)
- [Arcade Game Design Fundamentals](https://gamedesignskills.com/game-design/arcade/)
- [How Arcade Game Design Still Shapes Interactive Entertainment](https://game-ace.com/blog/arcade-game-design/)
- [Squeezing more juice out of your game design](https://www.gameanalytics.com/blog/squeezing-more-juice-out-of-your-game-design)
- [Juice in Game Design: Making Your Games Feel Amazing](https://www.bloodmooninteractive.com/articles/juice.html)
- [Pong AI and Game Mechanics](https://gamemechanics.fandom.com/wiki/Pong)
- [Pong Game Using AI](https://www.ijsrp.org/research-paper-0922/ijsrp-p12939.pdf)
- [Game UI Database - Title Screen](https://www.gameuidatabase.com/index.php?scrn=1)
- [Game UI Database - Pause Screen](https://www.gameuidatabase.com/index.php?scrn=44)
- [Breaking Down Breakout: System And Level Design](https://www.gamedeveloper.com/design/breaking-down-breakout-system-and-level-design-for-breakout-style-games)
- [The Impact Of Sound And Music In Arcade Gaming](https://www.homegamesroom.co.uk/blogs/types-of-arcade-machines-and-their-features/the-impact-of-sound-and-music-in-arcade-gaming)
- [7 HTML5 Game Design Mistakes to Avoid](https://www.htmlgoodies.com/html5/7-html5-game-design-mistakes-to-avoid/)
- [The Ultimate Guide to Game Design Anti-patterns](https://www.numberanalytics.com/blog/ultimate-guide-to-game-design-anti-patterns)
- [Principles Of HTML5 Game Design](https://www.smashingmagazine.com/2015/09/principles-of-html5-game-design/)

---
*Feature research for: HTML5 Arcade Pong Game*
*Researched: 2026-03-10*