Building Perfect Block Fit: Grid-based spatial reasoning in Expo

The Motivation Behind the Project

Perfect Block Fit combines 10x10 grid clearing with tangram mechanics to provide a satisfying, stress-free puzzle experience. The focus was on fluid drag-and-drop gestures and high-performance grid rendering. Available on the Google Play Store.

Core Features and Design Goals

• Freeform Piece Placement: Drag polyomino shapes onto the board with automatic snap detection.
• Simultaneous Line Clears: Clear rows and columns together to trigger rewarding visual explosions and score combos.
• No Clock Pressure: Relaxed, meditative gameplay loop without timers or countdown penalties.
• Child-Directed Ad Policy: 100% compliant with Google Play Families and COPPA guidelines.

Technical Implementation

• Utilized React Native Gesture Handler and PanResponder mechanics to calculate real-time board coordinate snapping and collision bounds.
• Optimized grid matrix re-renders by decoupling piece drag state from board state, preventing unnecessary frame drops on low-end devices.
• Added COPPA child-directed treatment and G-content rating restrictions directly in the AdMob SDK request pipeline.

The Technology Stack

Built with Expo, React Native Gesture Handler, TypeScript, and react-native-google-mobile-ads.

Final Reflections

Grid games succeed or fail based on gesture responsiveness and clearing satisfaction. The game is live on the Google Play Store.