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2026-02-21

Building Beautiful UI for Physics Games

How to make game interfaces that match the energy of your gameplay.

A physics game needs a UI that matches its energy. Too minimal and it feels cold. Too busy and it's distracting. Here's how we designed the Laundry Sort interface.

The Challenge: UI Within a 3D Game

Unlike traditional 2D games, our UI sits on top of an active 3D physics simulation. This means:

  1. Non-intrusive positioning: UI can't block the action
  2. Visual clarity: Must stand out from the colorful 3D scene
  3. Performance: Can't bog down physics calculations
  4. Responsive design: Works on mobile and desktop

The Design System

We built the UI around three zones:

Zone 1: Top HUD (Status)

[SCORE] ..................... [TIME]
  • Top-left shows the current score
  • Top-right shows time remaining
  • Both use monospace fonts and high contrast for readability at a glance
  • Time changes color as it runs out (green → red)

Zone 2: Center (Game World)

This is the action zone. We keep it completely clear to let the physics speak for itself.

Zone 3: Bottom (Controls & Instructions)

  • Shows game instructions before play starts
  • During gameplay: hidden (no distractions)
  • After gameover: Score submission and replay options

Color & Contrast

The HUD uses cyan and purple (matching our site branding) because:

  • They contrast with the warm-colored laundry (red, yellow, green)
  • They're easy to read on a dark background
  • They feel modern and energetic
  • They don't compete with the game world

Semi-transparent backgrounds with backdrop-blur-sm:

  • Makes text readable over the chaotic background
  • Creates visual separation without blocking the view
  • Feels elegant rather than opaque

Typography Choices

  • Monospace fonts for numbers (score, time): Feels technical and precise
  • Bold, uppercase for labels: Scannable at a glance
  • Large text: Players need to read at a glance while focused on the game

State Management

The UI has three distinct states:

State 1: Pre-Game

Show instructions
"SORT THE LAUNDRY!"
- Correct sort: +100 points
- Wrong bin: -25 points  
- Time limit: 2 minutes
[START GAME button]

State 2: Playing

Just HUD visible
Score & time visible
Everything else hidden

State 3: Game Over

Final score displayed
Username input field
[Submit & New Game] [Retry]

Mobile Responsiveness

The UI scales beautifully on mobile because:

  • Text sizes use responsive sizing (text-xs, text-sm, text-2xl)
  • Button sizes adjust for touch targets
  • HUD remains visible and readable even at 320px width
  • The 3D canvas fills the remaining space

Interactive Elements

We used visual feedback for every interaction:

  • Buttons highlight on hover
  • Inputs have focus states
  • Score changes flash on the screen
  • Time display color changes as deadline approaches

Performance Consideration

All UI updates are React state changes. The 3D canvas and physics run independently in the Three.js render loop, so:

  • Score updates don't stutter the physics
  • Time updates don't cause visual jank
  • Smooth 60fps even during intense action

Animation & Motion

We kept animations minimal:

  • State transitions fade smoothly (opacity changes)
  • Score flashes have quick pop-in/out animations
  • Time warnings gently shift color rather than flash

This avoids motion sickness while maintaining visual polish.

Accessibility Notes

For accessibility, we:

  • Use color + icons (not just color) to convey information
  • Provide plenty of contrast (3:1 minimum, usually 4:1+)
  • Keep text sizes above 12px
  • Use clear, simple language

The Results

The UI achieves its goals: ✓ Provides information at a glance ✓ Doesn't obstruct the gameplay ✓ Matches the energy of the physics action ✓ Looks great on all devices ✓ Runs without performance impact

The key is purposeful minimalism—every element earns its place on screen.

What UI design principles do you find most important in games? Drop your thoughts below!

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