Over the past three days I've been putting together a Minesweeper clone to go in my puzzle collection. As of now, it seems to be pretty much playable.

To write yet another Minesweeper clone in this day and age, you have to have some pretty impressive added value to avoid accusations of gratuitous reinvention of the wheel. My added value is that I use sophisticated grid construction to ensure that all puzzles generated can be solved without needing to guess. No more getting to the last four squares and finding you have no choice but to take a 50-50 gamble.

What I hadn't realised before actually writing this and playing with it is that it permits much denser grids. The Windows ‘Expert’ level has a mine density of a bit over 1 in 5, and it's already sailing close to the limit: I've generally found it quite rare to get to the end of an Expert grid without having to take a nasty risk. If you tried getting any denser with random generation, you'd just have a vanishingly small chance of actually completing anything. But with my intelligent generation, you can raise the mine density by nearly another factor of two: I've successfully played games on the same size of grid (30x16) with 190 mines. At that density there are barely any blank areas to work round the edges of; almost the whole grid is taken up by fiddly work involving squares marked between 3 and 6, and there's no let-up. And it's fun.

Now I just need to find a way to go to sleep tonight without dreaming about Minesweeper…