Building Minesweeper with mobile-first interaction design
The Motivation Behind the Project
Minesweeper is a familiar game, but recreating it well still takes careful interaction design. I built this Expo version to keep the rules readable, the board responsive, and the core loop satisfying on a phone screen.
Core Features and Design Goals
- Three difficulty levels: a simple way to keep the game useful for new and experienced players.
- Safe first click: the game avoids punishing the player before the round really starts.
- Chord reveal and flag cycling: the small mechanics that make the classic game feel complete.
- Live timer and visual themes: polish that keeps the game pleasant to replay.
Technical Implementation
- Implemented a flood-fill reveal algorithm that recursively uncovers adjacent empty cells on tap, with a safe first-click guarantee that regenerates the mine layout if the initial cell is a mine.
- Built chord reveal (simultaneous neighbor reveal when flag count matches) and flag cycling (blank → flag → question → blank) as core interaction mechanics that replicate the desktop Minesweeper experience on touch.
- Designed a theme system with 5 switchable visual skins that remap all cell colors, borders, and backgrounds — unlocked progressively to create a small reward loop tied to gameplay milestones.
Challenges I Faced Along the Way
The trickiest part of Minesweeper is getting the flood-fill reveal to feel correct. When the user taps an empty cell, the algorithm recursively reveals all adjacent empty cells — but the recursive approach can cause a noticeable frame drop on larger boards because React re-renders the entire grid on each state update. I solved this by batching all the cells that need to be revealed into a single state update, computing the full flood-fill result before triggering any re-render. The safe first-click guarantee also required careful implementation: if the user's first tap lands on a mine, the entire board is regenerated with the mine moved to a random non-adjacent cell, but this needs to happen fast enough that the user never notices the regeneration.
The Technology Stack
Built with Expo and React Native. The board is rendered as a pure state-driven grid where each cell's state (hidden, revealed, flagged, mine) is tracked in a 2D array. React Native Reanimated powers smooth cell reveal animations and timer transitions across all five visual themes.
Final Reflections
It is a good reminder that even a classic game can teach a lot about state updates, responsiveness, and careful UI timing. The project proved that performance optimisation in React Native is often about minimising the number of renders, not making individual renders faster.