A squishy 3D platformer across ten named sections, every asset drawn in code. Both Qwen runs finished for around a dollar; both Opus runs spent over twenty and neither ended cleanly.
"Jelly Jungle — 3D jungle run" is one prompt run by 2 models: Qwen 3.8 Max and Opus 5.2 of 4 finished; 4 measured locally.
Models
2
Completed
2 of 4
Cheapest completed run
Qwen 3.8 Max — $1.02
Measured locally in Bench Arena: tokens reconciled on the harness log, cost recomputed from them.
Output
Qwen 3.8 Max
Qwen 3.8 Max
Opus 5
Opus 5
Prompt244 lines · EN
Build a complete browser-based 3D game called "Jelly Jungle" using Three.js with plain HTML, CSS, and JavaScript (unless the existing project already uses a framework).
Create an original arcade obstacle course inspired by colorful toy worlds and jungle playgrounds. Do NOT copy assets, characters, level layouts, or visuals from any existing game.
## Core Gameplay
- Single-player 3D obstacle course.
- Control a cute jelly-like blob character with squash-and-stretch animation.
- Third-person follow camera.
- Objective: reach the finish line as quickly as possible.
Controls:
- WASD / Arrow Keys → Move
- Space → Jump
- Shift → Dash forward with a quick jelly dive
- R → Restart from latest checkpoint
Keyboard handling — treat this as a requirement, not a detail:
- Movement is relative to the camera. Pressing forward moves the blob away from the camera,
whatever direction the camera is currently facing. Never move along fixed world axes.
- Read `event.code`, not `event.key`, so the keys work regardless of modifiers and caps.
- `event.code` describes a physical QWERTY position, so it must not be the only mapping.
Also accept the AZERTY letters: `KeyZ` and `KeyQ` do the same as `KeyW` and `KeyA`.
A player on a French keyboard must be able to press either the ZQSD block or the keys
printed W/A/S/D and move in the direction they expect.
- Arrow keys stay a full alternative to all of the above.
- Call `preventDefault()` on the movement and jump keys so the page never scrolls under the
game.
Movement should feel:
- Responsive
- Forgiving
- Arcade-like
- Slightly bouncy
- Easy to control
- Never overly physics-based
---
## Level Design
Create one polished jungle course lasting around 2–3 minutes.
Sections:
### 1. Jungle Entrance
- Bright leaves
- Giant flowers
- Animated butterflies
- Wooden starting platform
### 2. Mushroom Bounce Garden
- Huge colorful mushrooms acting as trampolines
- Different bounce heights
- Floating spores particles
### 3. Sticky Slime Swamp
- Green slime pools that slow movement
- Small safe lily pads
- Bubble particles rising from slime
### 4. Swinging Vine Crossing
- Giant vines swinging back and forth
- Jump timing challenge
- Leaves fall occasionally
### 5. Rolling Fruit Hill
Large fruits continuously roll downhill:
- Watermelons
- Oranges
- Blueberries
- Pineapples
Player must dodge them while climbing.
### 6. Bubble Launch Zone
Large floating bubbles launch the player upward.
Include:
- Multiple aerial platforms
- Mid-air collectibles
- Soft landing areas
### 7. Jungle Log Bridge
A narrow wooden bridge with:
- Rotating logs
- Small gaps
- Gentle swinging motion
### 8. Flower Spinner Arena
Large spinning flowers with rotating petals that push the player away.
### 9. Giant Frog Pads
Moving lily pads that travel between ponds.
### 10. Rainbow Waterfall Finish
A colorful ramp leading into a glowing finish flower portal.
---
## Checkpoints
Place checkpoints throughout the course.
When activated:
- Blooming flower animation
- Color burst particles
- Pleasant sound effect (if audio is implemented)
If player falls:
- Fade out briefly
- Respawn at latest checkpoint
- Small splash particle effect
Recovery should take under two seconds.
---
## Character
Create an original jelly creature.
Features:
- Rounded body
- Tiny arms
- Tiny legs
- Cute face
- Large expressive eyes
- Squash-and-stretch while moving
- Jiggle slightly when landing
- Wobble while idle
Do not resemble Fall Guys characters.
---
## Obstacles
Include interactive jungle-themed obstacles:
- Bouncy mushrooms
- Swinging vines
- Rotating flowers
- Rolling fruit
- Slime puddles
- Bubble launchers
- Wind gust flowers
- Falling coconuts
- Rotating wooden logs
- Moving lily pads
Every obstacle should have smooth animation.
---
## Visual Style
Create a vibrant toy-like jungle.
Environment should include:
- Giant flowers
- Oversized mushrooms
- Palm trees
- Ferns
- Glowing plants
- Rainbow waterfalls
- Floating pollen
- Butterflies
- Fireflies
- Floating leaves
- Soft clouds
- Cartoon rocks
Lighting:
- Bright daytime
- Soft ambient lighting
- Warm sunlight
- Bloom-like glow where appropriate
Materials:
- Glossy
- Saturated colors
- Rounded geometry
- No realistic textures
Everything should feel handcrafted and playful.
---
## Effects
Add satisfying particles for:
- Jump
- Landing
- Dash
- Bounce
- Checkpoint
- Respawn
- Finish
- Falling leaves
- Floating spores
- Bubble pops
Camera effects:
- Small landing shake
- Slight FOV increase while dashing
- Smooth follow camera
- Camera lag for polished movement
---
## UI
Start Screen
- Jungle logo
- "Jelly Jungle"
- Play button
- Simple animated jungle background
HUD
- Timer
- Current checkpoint
- Best time
- Restart hint
---
## Acceptance criteria
- The project opens in a browser and plays immediately, with zero console errors.
- Every control listed above works: forward, back, left, right, jump, dash, restart —
from the ZQSD block, from the keys printed W/A/S/D, and from the arrow keys.
- Movement follows the camera: after the camera has swung around, pressing forward still
moves the blob away from the camera, not toward a fixed compass direction.
- The blob squashes and stretches while moving, jiggles on landing, and wobbles when idle.
- Each of the ten sections is present and reachable in one continuous run from start to
finish.
- Every obstacle type listed moves or animates; none is decorative geometry.
- Falling respawns at the latest checkpoint in under two seconds.
- The timer, checkpoint counter and best time update correctly, and best time survives a
restart.