We were initially inspired by Google's April Fool's Day version of Pacman - we wanted to recreate a classic arcade game in real, physical space. Our app does not use GPS coordinates - instead, it uses readings from the Android accelerometer and magnetometer to determine the user's velocity, direction and position at any given instant relative to the starting position. This makes the game playable in any place, regardless of internet connectivity, actual location, or terrain. To click on a cell, one must 'walk' over its real world coordinates. In effect, it allows you to imagine a minefield around you, no matter where you are: you can take Minesweeper out of your Windows Menu, and into your real world.
Our target user is essentially anyone up for a fun walk in the park (or anywhere, for that matter).
We're definitely happy with our rough implementation of the sensor-based movement. We made a few approximations, but the end result is pretty accurate. Using just an accelerometer and magnetometer to simulate movement around a real-world, flexible, coordinate system was definitely challenging. Additionally, our freshman knowledge of data structures helped us out quite a bit while designing the underlying model that represents the minefield.