"Something sinister happens every night in a cursed mansion in Vienna. Some years have passed since the second plague epidemic, and you are the only descendant of the Malstrum's family who will dare enter the mansion, and discover what happened in that haunted place."
Many, many years ago my brothers Andres, Edmundo and I discovered the classic game 'Shadowgate' on our first family computer; a Macintosh Plus. This title was basically the first game that made us want to create a game ourselves. Not even being able to beat it, we started elaborating our own version and after several months of drawing pixel by pixel, in 1989 we ended up with all the art assets of 'The Malstrum's Mansion'. The problem was: The three of us were aspiring artists and designers, but not programmers. So after several attempts of trying to bring the project into life (we even tried to implement it with Hypercard - a early Powerpoint type program), we simply moved on and the game was left aside.
Many years later we formed a independent game studio named ACE Team and started working on our debut title 'Zeno Clash' (a first person melee fighting game running on the Source Engine). As we were nearing completion of the game, we had the idea of using The Malstrum's Mansion as some sort of viral advertising for Zeno Clash, but we were not sure how. Juan Briones programmed the game in Flash and we ended up using it as an April's fools joke, just some weeks before the release of ACE Team's first commercial game.
So that is the history of The Maltrum's Mansion. The game was drawn and designed in 1989 for a Mac Plus, but it didn't see the light until April 2009. To preserve the classic feel of the game we even made it run on a fake 'Apple' OS and even implemented some retro DRM (you just have to read the readme.txt in the game's directory). The only warning is that the game has no save feature, but neither did the version of Shadowgate that we played. If you get stuck and don't have the patience to get through it, you can always search for walkthroughs in Youtube.
P.S: The 512 x 384 resolution that this flash has was around the full screen resolution of a Mac Plus those days.