This is a freeware adventure game based on the King's Quest series.
http://www.tsl-game.com/
It is very professionally done (at least, looking at the visuals). Since I don't have a half-decent Windows machine, it is unlikely I will be able to play it though.
Another freeware adventure game based on another popular classic series, Zack McKfracken: Between Time and Space, has been complete for a while but only available in German. The English version is getting nearer though and they have a new website:
http://www.mckracken.net/