OK, to get the secret ending you have to get the dynamite from the armory, then click on the boxes next to the arrow that says elevator. All this after getting all 7 letters.
Bug report: While traveling, you can first select the area that you're already in to travel very quickly, then select a different area while the travel bar is charging. You'll travel to the new area in a greatly reduced amount of time.
This game is fun but the bugs are really bad. My character got stuck so I had to restart the game after finishing what I think was the last death gate quest. When I reloaded I was still on the quest but I couldn't finish it by talking to the NPC and the death gates won't reappear so I can't do anything else and I don't feel like starting over. This game could easily be a 4 or 5 but because of the bugs I'm giving it a 3.