Short explanation: The WLV format is different allowing for some extra variables in the game environment to be modified, I have few other thingys that I plan on making adventure on soon
Long explanation: WA1 1.04 added an additional level format that allows LevelTimer and Tile map to be modified. No editor can do that, not even MNIK's so I did some hex editing around it. You can get a LevelFormat104 by saving an adventure and taking the SaveFile.wlv, but you need to modify quite a lot of things there.