Stop press! DROD now has a Flash version!
...okay I'm pretty sure most people that read this scratched their heads, looked at the ugly screenshot and went "what?" :)
Well, the Deadly Rooms Of Death (or DROD for short) are a series of games that offer hardcore puzzles to anyone that dares try them. The movement is turn-based and you can only move from one square to the other. The hero carries a sword that rotates independently of his movement, so this leads to a great deal of flexibility (although each swing of the sword costs one movement point). There are quite a few enemies with very varying AI patterns - my favorites are the grunt-like roaches though :). Each tile is not the same as the other either, there are doors (and even doors are of 3-4 different types), loose slabs, direction arrows, water and so on, so your strategy must adapt to each screen's conditions. In certain screens, some cutscenes are triggered which reveal the story as you go along (and of course you can skip them if you really don't care).
I must stress that while the game starts easy enough, it soon gets quite hard and requires lots of forethought and replays in order to finish certain screens. Personally I've spent many hours playing DROD and I must say that it really helped me optimizing stuff after finishing some levels ;).
If after all these warnings you still want to try it, I can't do anything else than point you to the online version. Good luck! (and don't blame me if you lose your sleep, sanity or hair :P)