DROD (Deadly Rooms Of Death) is a turn-based puzzle game played on a 2D board with a top-down view. Your task is to exterminate the various monsters in a dungeon, room by room and level by level. The game has no random element and no real-time element, making it rather like chess. It uses very simple keyboard controls. The game elements can be combined by level designers ("dungeon architects") to make some extremely varied and challenging puzzles. Various editions of DROD have been available for some time as payware downloadables (with free demo versions) but the "King Dugan's Dungeon" edition has recently been released as a series of Adobe Flash Player programs (play free online in a browser, no installation required).
Flash DROD: http://caravelgames.com/Articles/Gam...DROD/KDDL.html
More information about DROD: http://en.wikipedia.org/wiki/Drod
(I've no connection with the publishers other than as a satified customer.)