Every 1000 years, the planets align such that a gateway to another plane can be opened. This gateway is the Dark Portal. Beyond it lie forces of chaos and evil that had best not even be imagined. This year, in revenge for his expulsion from the Council of Mages for necromancy and other perverse experiments, the Warlock Lord seeks to open the portal. As he is of such immense power, he can manipulate the portal with his own innate magical ability, and he is making great strides in opening it. The dark clouds and lightning lingering in the sky almost constantly these days tell as much.
Still, there is hope for the land. Legends tell of a great relic called the Staff of Ages, that can boost the magical abilities of its user to levels even greater than the Warlock Lord's. This is, truly, the only hope for closing the portal and standing against this evil force. As the legends go, only one with the royal blood can use the staff, so the last king of the land sets out to ensure he still has a land to rule...
This is not a typical DM Dungeon. Though it does still possess the core mechanics of wandering around, avoiding pits, pushing on wall triggers, casting spells, using items, and so on, the actual gameplay is very different. It is 100% puzzle-based. These puzzles may be based on logic, button-pushing, items, spotting small details, speed, or, often, combinations of the above, using mechanics both familiar and not familar to DM players.Even combat is puzzle-based, in that the proper item or spell used on the monster will instantly defeat it, and other attacks will have no effect at all.
This means that training is rather worthless. Just as in DM, though, not every monster can or needs to be killed.
It is rather inspired by the "Shadowgate" game on the NES and PC, though many of the puzzles have been expanded and altered to fit the DM
mythos. The name is a pun on "Shadowgate," to be truthful. ;)