game-feel（游戏感觉）

Game Feel Skill

A framework for understanding, measuring, and creating satisfying game controls based on Steve Swink's comprehensive analysis.

Core Definition

Game feel is the tactile, kinesthetic sense of manipulating a virtual object. It's the sensation of control—that visceral feeling of steering, jumping, and interacting that exists somewhere between player and game.

"Game feel is an invisible art. If a designer's done their job correctly, the player will never notice it. It will just seem right."

The Three Building Blocks

Game feel requires all three elements working together:

Human Perception Thresholds

The Correction Cycle

Players perceive, think, and act in ~240ms cycles:

• Perceptual processor: ~100ms
• Cognitive processor: ~70ms
• Motor processor: ~70ms

Critical Thresholds

"At 50ms response, the game feels like an extension of your body. Above 100ms, you notice lag. Above 240ms, real-time control is broken."

See: references/perception-thresholds.md

The Six Metrics of Game Feel

1. Input

The physical device and signals it sends.

Measure: Sensitivity, states, signal types (Boolean vs continuous), physical ergonomics

2. Response

How input maps to game state changes.

Measure: Direct vs indirect mapping, simulation complexity, ADSR envelopes

3. Context

The spatial environment providing meaning to motion.

Measure: Object spacing relative to avatar speed, collision density, level layout

4. Polish

Effects that emphasize and sell interactions.

Measure: Particles, screen shake, animation sync, sound design

5. Metaphor

What the game represents and expectations it creates.

Measure: Realism vs abstraction, player expectations, genre conventions

6. Rules

Game rules that affect moment-to-moment feel.

Measure: Health systems, risk/reward, state changes, ability unlocks

See: references/six-metrics.md

The ADSR Envelope for Game Feel

Borrowed from audio synthesis, describes how response changes over time:

     Sustain ___________
    /                   \
   / Attack      Decay   \ Release
  /                       \
_/                         \_____

Key insight: Most "floaty" vs "tight" feelings come from Attack and Release times.

See: references/adsr-tuning.md

Common Feel Vocabulary

Simulation Fundamentals

Position vs Velocity vs Acceleration

The Asteroids Principle

Separate thrust from rotation for expressive space-feel:

• Rotation: Direct, instant (no simulation)
• Thrust: Adds force in facing direction (simulated)
• Result: Ship feels on-the-edge-of-control but never actually out of control

The Mario Principle

Separate horizontal and vertical systems:

• Horizontal: Acceleration, max speed, deceleration, run modifier
• Vertical: Jump force, gravity, fall gravity (3x normal!), terminal velocity
• Button hold time affects jump height (with min/max limits)

See: references/simulation-recipes.md

The Mario Jump Recipe

The most-analyzed jump in game history:

Horizontal Movement

Walk acceleration → Walk max speed
Run acceleration → Run max speed (B held)
Air acceleration (reduced)
Deceleration (same for walk/run)

Vertical Movement

Initial jump force (instant, large)
Gravity (constant, moderate)
Jump button hold → extends upward force (with max time)
Early release → force artificially set to low value
Apex detection → gravity triples for descent
Terminal velocity cap

The "Hack" That Makes It Work

When player releases jump early:

1. Check if upward velocity > threshold
2. If yes, instantly set velocity to preset low value
3. This creates consistent arc shapes regardless of release timing

See: references/mario-mechanics.md

Polish That Matters

The Three-Tier Impact System

Light / Medium / Hard impacts each get:

• Distinct animation
• Distinct sound
• Distinct visual effect (particles, screen shake)

Sound-Motion Harmony

• Rising pitch = rising motion (Mario's jump sound)
• Impact sounds match visual scale
• Footsteps sync with animation frames
• Material-specific sounds (metal, grass, stone)

Crossover Sensation

Multiple mechanics should feel bound by the same physics:

• Swimming feels floaty *because* running feels grounded
• Flying defies *the same gravity* that affects jumping
• Contrast creates perceived consistency

See: references/polish-effects.md

Context: Level Design for Feel

Spatial Relationships Must Match Mechanics

• Jump heights → platform heights
• Run speed → corridor widths
• Stopping distance → gap sizes before hazards

The "Just Right" Principle

Objects should be spaced so the intended move *just barely* works:

• Long Jump gaps: exactly Long Jump distance
• Triple Jump heights: exactly Triple Jump apex
• Creates sense of mastery when executed

Soft Boundaries

Use physics to guide, not walls to block:

• Steep inclines cause sliding (Mario 64)
• Water slows movement
• Winds push in intended directions

"Players don't feel the direct intervention of the designer. The limit feels like a logical consequence rather than an overt constraint."

See: references/spatial-context.md

Debugging Feel Problems

Principles of Good Game Feel

1. Predictable special moves — Fixed trajectories for precision maneuvers
2. Variable basic moves — Expressive range for moment-to-moment control
3. Consistent abstraction — Simple physics, but self-consistent
4. Exceed metaphor expectations — Feel more real than graphics suggest
5. Polish harmonizes — Sound, visual, animation tell same story
6. Context matches capability — Level design respects avatar limits
7. Response < 100ms — Maintain instantaneous feel
8. Contrast creates variety — Different mechanics feel different

Quick Reference: Classic Feel Profiles

Asteroids (Floaty Space)

• Thrust separate from rotation
• Very low friction (4+ seconds to stop)
• Screen wrap containment
• Rotation: instant, no simulation

Super Mario Bros (Platformer Gold Standard)

• Separate horizontal/vertical systems
• Variable jump height (button hold)
• Triple gravity on descent
• Run modifier changes acceleration AND max speed
• Reduced air control

Mario 64 (3D Translation)

• Camera-relative thumbstick control
• Incline-based sliding physics
• Multiple jump types with fixed trajectories
• Carving turn interpolation
• Ground pound as precision landing tool

See: references/classic-profiles.md

Key Mantras

• "The game should feel like an extension of your body."
• "Separate systems, consistent world." — Independent mechanics, unified physics.
• "Exceed the metaphor." — Feel better than it looks.
• "Fixed for precision, variable for expression." — Special moves vs basic moves.
• "Polish is not optional." — Effects sell the interaction.
• "240ms is the wall." — Response time ceiling for real-time control.