Add'em Up - Math Puzzle Game - Puzzle Game

Please use Three.js to generate a **mobile-first game** with the theme "Add'em Up". Please read the following detailed game design requirements first, and then generate the code accordingly: ### 1. Assets & Environment * **Visual Style:** A modernized "Retro-Casual" aesthetic. Use a clean, orthographic camera view looking down at the game board (tilted slightly for 3D depth). * **Game Pieces:** The core assets are 3D spheres or rounded cylinders representing "Number Tokens". * **Colors:** Use a vibrant, high-saturation palette based on the screenshot (Bright Cyan, Hot Pink, Lime Green, Orange, Yellow). Each number (1-9) should have a distinct, fixed color. * **Textures:** Each token must display a large, white, bold number. To pay homage to the original game, add simple, procedural "googly eyes" or a simple smiley face texture above the number on each sphere. * **Board:** A 5x5 or 6x6 grid slot system. The background should be a soft, matte grey or off-white to ensure the colorful tokens pop. * **Effects:** When tokens are successfully added/cleared, use a particle explosion effect in the color of the resulting number. * **Mobile Optimization:** Use `BoxGeometry` or low-segment `SphereGeometry` for tokens to keep draw calls low. Reuse materials. Ensure shadows are baked or use a simple directional light without expensive real-time soft shadows. ### 2. Audio Requirements * **BGM:** A "Brain Teaser" style track—looping, rhythmic, light synth-pop or marimba-based. It should be relaxing but keep the player focused (80-100 BPM). * **Sound Effects:** * **Select/Tap:** A soft "pop" or bubble sound. * **Merge/Add:** A satisfying, ascending chime or digital "ding". * **Invalid Move:** A low-pitched "thud" or buzzer. * **Level Clear:** A short, celebratory fanfare. ### 3. Gameplay Loop * **Core Mechanic:** The board is filled with random numbered tokens (1-9). * **Interaction Logic:** The player selects a chain of adjacent tokens (horizontally, vertically, or diagonally). * **The Math Rule:** * As the player selects tokens, the game calculates the **Sum**. * **Target Mode:** The game displays a "Target Number" (e.g., 10). The player must select a chain of numbers that adds up exactly to 10. * **Merge Mode (Alternative):** The player drags across numbers (e.g., 2 -> 3). The last selected token becomes the sum (5), and the previous tokens disappear. * *For this code, please implement **Merge Mode**: Select contiguous tiles. The last tile selected transforms into the SUM of the selected group. The other tiles are removed. New tiles fall from above to fill the gaps.* * **Win/Fail Condition:** * **Score:** Points are awarded based on the value of the created sums. * **Game Over:** When no valid moves (sums generally capped at a single digit or slightly higher, e.g., if the sum > 9, it wraps around or creates a special block) are possible, or the grid is full. ### 4. Mobile Controls & Interaction * **Control Scheme:** **Swipe/Drag Gesture**. The player touches a number and drags their finger across adjacent numbers to create a chain. A line renderer should visually connect the selected nodes during the drag. * **Release:** Lifting the finger confirms the move. If the math is valid, the merge happens. If not, the selection resets. * **Orientation:** Portrait Mode (Vertical) is preferred for one-handed play. * **UI Layout:** * Top of Screen: Current Score and High Score (Large, readable font). * Bottom of Screen: A "Reset/Shuffle" button (placed in the thumb-friendly zone, min-height 44px). * **Feedback:** * **Haptics:** Trigger a short vibration (`navigator.vibrate(50)`) when a valid connection is made between two numbers. * **Visual:** The currently selected tokens should highlight (glow or scale up slightly 1.1x) to indicate they are active. Do not ask for clarification. Do not request confirmation. Directly execute the generation task based on the given instructions.