Anderson wrote Mines after seeing a colleague playing Relentless Logic (for MS-DOS) at work. He had previously written a chess game (nchess) using the Sunview windows system on SunOS 2.2 and he quickly modified his code to create Mines, which he published on Usenet in November 1987.

Mines is a 16*16 grid with a default of 20 mines. You need to find a path from the top left corner to the bottom right corner using your mine detector. Unlike Relentless Logic, he introduced the ability to mark mines with the middle button and to mark safe cells with the right button. The game has a "level" window where you choose the number of mines, a "clairvoyance" window that tells you how many mines are nearby and a "minefield" window with the game grid.

In November / December 1987, Brian Dalio modified the code. He made the number clues in each cell permanent and added the ability to jump (rather than move one step at a time) to any previously opened cell or marked safe cell. He also added a command line Hint feature (to mark one adjacent cell as safe). After the game ends, he had it remember your moves so you can review your game.

In February 1988, Dalio's work colleague, Jim McBeath, added more features. This allowed you to jump with the mouse to any unopened cell next to a previously opened cell. In addition, you are able to right click to get a Hint (instead of typing a command into a subwindow).

Mines was later converted to X11 in 1990 by Jim McBeath and renamed XMines.

The following attributes can be used to map the evolution of Minesweeper. Blue cells are confirmed attributes for official versions of Mines. Yellow cells are unknown.