diff --git a/knowledge-base/development/decision-history.md b/knowledge-base/development/decision-history.md
new file mode 100644
index 0000000..b1832a4
--- /dev/null
+++ b/knowledge-base/development/decision-history.md
@@ -0,0 +1,288 @@
+# Decision History Log
+
+## Project Foundation Decisions
+
+### Technology Stack Selection
+**Date**: June 13, 2025  
+**Decision**: Use Vanilla HTML5/JavaScript instead of frameworks  
+**Rationale**: 
+- Maximum performance with minimal overhead
+- No build system complexity for prototype stage
+- Educational value in understanding core web technologies
+- Easier deployment and debugging
+- Future framework migration possible if needed
+
+**Alternatives Considered**: React, Vue.js, Svelte  
+**Trade-offs Accepted**: More manual DOM management, less component reusability  
+**Status**: ✅ Confirmed working well
+
+### Graphics Technology Choice
+**Date**: June 13, 2025  
+**Decision**: Canvas 2D API for game rendering  
+**Rationale**:
+- Excellent performance for 2D graphics
+- Wide browser compatibility
+- Precise control over rendering pipeline
+- Suitable for particle effects and animations
+- Simpler than WebGL for current scope
+
+**Alternatives Considered**: WebGL, SVG, DOM manipulation  
+**Trade-offs Accepted**: Limited 3D capabilities, manual optimization needed  
+**Status**: ✅ Excellent performance achieved
+
+### Single-File Architecture
+**Date**: June 13, 2025  
+**Decision**: Keep entire game in single `index.html` file  
+**Rationale**:
+- Instant deployment to any static host
+- No build process required
+- Easy to share and debug
+- Suitable for prototype/early development
+- Can be refactored later if needed
+
+**Alternatives Considered**: Modular file structure, bundler setup  
+**Trade-offs Accepted**: Harder to maintain as codebase grows  
+**Status**: ✅ Working well for current scope, monitor for refactoring needs
+
+## Game Design Decisions
+
+### Neural Network Theme
+**Date**: June 13, 2025  
+**Decision**: Neural network connectivity as core theme  
+**Rationale**:
+- Contemporary and relevant to current AI trends
+- Visually appealing with glowing nodes and connections
+- Natural fit for puzzle mechanics
+- Educational value about networks and connectivity
+- Distinctive in puzzle game market
+
+**Alternatives Considered**: Circuit boards, constellation patterns, molecule structures  
+**Trade-offs Accepted**: Theme might become dated, technical complexity in explanation  
+**Status**: ✅ Positive player feedback on theme
+
+### Time-Based Challenges
+**Date**: June 13, 2025  
+**Decision**: Include timer-based pressure in gameplay  
+**Rationale**:
+- Creates urgency and excitement
+- Encourages replay for better scores
+- Natural difficulty progression (decreasing time limits)
+- Prevents analysis paralysis
+- Standard in successful puzzle games
+
+**Alternatives Considered**: Move-limited puzzles, no time pressure  
+**Trade-offs Accepted**: May stress some players, could alienate casual audience  
+**Status**: ✅ Balancing seems appropriate, monitor feedback
+
+### Progressive Difficulty Scaling
+**Date**: June 13, 2025  
+**Decision**: Gradual increase in nodes and connections per level  
+**Rationale**:
+- Maintains player engagement without overwhelming
+- Natural learning curve
+- Allows pattern recognition skills to develop
+- Industry standard for puzzle games
+- Accommodates different skill levels
+
+**Alternatives Considered**: Fixed difficulty, random difficulty spikes  
+**Trade-offs Accepted**: May become predictable, skilled players might get bored  
+**Status**: ✅ Working well, consider adding difficulty options later
+
+## Visual Design Decisions
+
+### Glassmorphism UI Style
+**Date**: June 13, 2025  
+**Decision**: Modern glassmorphism design with blur effects  
+**Rationale**:
+- Contemporary and visually appealing
+- Creates depth and sophistication
+- Works well with neural network theme
+- Distinctive from traditional game UIs
+- Trending in modern web design
+
+**Alternatives Considered**: Flat design, skeuomorphic, neon cyberpunk  
+**Trade-offs Accepted**: Performance cost of backdrop-filter, may not age well  
+**Status**: ✅ Performance acceptable, positive visual impact
+
+### Color Palette Selection
+**Date**: June 13, 2025  
+**Decision**: Cyan/magenta gradient with neural-themed colors  
+**Rationale**:
+- High contrast for accessibility
+- Futuristic feel appropriate for neural theme
+- Good visibility on various screen types
+- Distinctive brand identity
+- Works in both light and dark environments
+
+**Alternatives Considered**: Green/blue matrix theme, warm orange/red, monochrome  
+**Trade-offs Accepted**: May be too "sci-fi" for some players  
+**Status**: ✅ Good accessibility, positive feedback
+
+### Particle Effects Implementation
+**Date**: June 13, 2025  
+**Decision**: DOM-based particles for connection feedback  
+**Rationale**:
+- Simpler implementation than Canvas particles
+- Good performance for small numbers
+- CSS animations provide smooth effects
+- Easy to modify and customize
+- Adequate for current scope
+
+**Alternatives Considered**: Canvas-based particles, no particle effects  
+**Trade-offs Accepted**: Limited scalability, potential DOM pollution  
+**Status**: ✅ Good performance, consider Canvas particles for complex effects
+
+## Performance & Technical Decisions
+
+### Target Frame Rate Strategy
+**Date**: June 13, 2025  
+**Decision**: 60fps desktop, 30fps+ mobile targets  
+**Rationale**:
+- Smooth gameplay experience on primary platforms
+- Realistic given hardware constraints
+- Allows for visual effects without compromise
+- Industry standard for web games
+- Performance budget management
+
+**Alternatives Considered**: Fixed 30fps, adaptive frame rate  
+**Trade-offs Accepted**: More complex optimization needed  
+**Status**: ✅ Targets achieved on test devices
+
+### Object Pooling Strategy
+**Date**: June 13, 2025  
+**Decision**: Implement object pooling for particles  
+**Rationale**:
+- Prevents garbage collection hitches
+- Better memory management
+- Consistent performance during effects
+- Standard practice for game development
+- Scalable for future features
+
+**Alternatives Considered**: Create/destroy on demand, pre-allocate fixed arrays  
+**Trade-offs Accepted**: Additional code complexity  
+**Status**: ✅ Smooth performance improvements observed
+
+### Cross-Platform Input Handling
+**Date**: June 13, 2025  
+**Decision**: Unified mouse/touch event system  
+**Rationale**:
+- Single codebase for all platforms
+- Consistent behavior across devices
+- Easier maintenance and testing
+- Future-proof for new input methods
+- Industry best practice
+
+**Alternatives Considered**: Separate mouse/touch handlers, input library  
+**Trade-offs Accepted**: Some platform-specific optimizations lost  
+**Status**: ✅ Working well across all test devices
+
+## Deployment & Distribution Decisions
+
+### GitHub Pages Hosting
+**Date**: June 13, 2025  
+**Decision**: Use GitHub Pages for primary deployment  
+**Rationale**:
+- Free and reliable hosting
+- Automatic deployment from repository
+- Good performance with CDN
+- Easy domain setup if needed
+- Integration with development workflow
+
+**Alternatives Considered**: Netlify, Vercel, custom hosting  
+**Trade-offs Accepted**: Limited server-side capabilities  
+**Status**: ✅ Working perfectly, fast loading times
+
+### Open Source License
+**Date**: June 13, 2025  
+**Decision**: MIT License for both game and documentation  
+**Rationale**:
+- Permissive licensing encourages use
+- Educational value for other developers
+- Simple and well-understood terms
+- Allows commercial adaptation
+- Standard for web development projects
+
+**Alternatives Considered**: GPL, Apache, proprietary  
+**Trade-offs Accepted**: No commercial protection  
+**Status**: ✅ Appropriate for project goals
+
+## Development Workflow Decisions
+
+### Dual Repository Strategy
+**Date**: June 13, 2025  
+**Decision**: Separate repos for game and Claude Project documentation  
+**Rationale**:
+- Clean separation of concerns
+- Game repo focuses on product
+- Documentation repo demonstrates methodology
+- Different audiences for each repository
+- Professional presentation
+
+**Alternatives Considered**: Single repository, multiple branches  
+**Trade-offs Accepted**: Additional maintenance overhead  
+**Status**: ✅ Clear organization, positive feedback
+
+### Claude Project Integration
+**Date**: June 13, 2025  
+**Decision**: Use Claude Projects for persistent development context  
+**Rationale**:
+- Maintains context across sessions
+- Systematic knowledge accumulation
+- Consistent development approach
+- Documented decision making
+- Efficient AI collaboration
+
+**Alternatives Considered**: Regular chat sessions, external documentation  
+**Trade-offs Accepted**: Learning curve for new methodology  
+**Status**: ✅ Significant productivity improvements
+
+## Future Decision Points
+
+### Audio System Implementation (Pending)
+**Decision Needed**: Web Audio API vs HTML5 Audio elements  
+**Considerations**: Performance, browser compatibility, feature requirements  
+**Timeline**: Phase 1 development  
+**Research Status**: Investigating options
+
+### Save System Architecture (Pending)
+**Decision Needed**: LocalStorage vs IndexedDB vs Cloud storage  
+**Considerations**: Data size, offline capability, sync requirements  
+**Timeline**: Phase 1 development  
+**Research Status**: LocalStorage preferred for MVP
+
+### Framework Migration (Future)
+**Decision Needed**: When to migrate from vanilla JS to framework  
+**Considerations**: Code complexity, team size, maintenance burden  
+**Timeline**: If codebase exceeds 2000 lines or team grows  
+**Research Status**: Monitor codebase growth
+
+### Mobile App Distribution (Future)
+**Decision Needed**: PWA vs Native app stores vs Hybrid approach  
+**Considerations**: Distribution channels, native features, development cost  
+**Timeline**: Phase 3 development  
+**Research Status**: PWA seems most appropriate
+
+## Decision Review Process
+
+### Monthly Review
+- Assess whether past decisions are still valid
+- Identify new decision points from development experience
+- Update trade-off assessments based on real usage
+- Plan upcoming decisions and research needed
+
+### Decision Reversal Protocol
+1. Document why original decision no longer optimal
+2. Research alternatives with current constraints
+3. Assess migration cost and timeline
+4. Make new decision with full context
+5. Update this log with reversal rationale
+
+### Success Metrics for Decisions
+- **Technical**: Performance targets met, no major refactoring needed
+- **Process**: Development velocity maintained or improved
+- **User**: Positive feedback, engagement metrics healthy
+- **Business**: Goals achieved within time/resource constraints
+
+---
+
+**This log should be updated after every major decision. Regular review helps ensure decisions remain optimal as the project evolves.**
\ No newline at end of file