Awesome, very glad that you liked it! :)
Well, the twist was one of the first ideas that I had for the game, writing much of the story around it.
The 5 keys are hidden around the ship, meaning you have to explore it thoroughly, for example, one is in the "Fire station" on the "Bizz Plaza", another in the "labs" on the "lower level" and so on...
Remember to play "Stories of New Eden", as well, they will tell you more of the story, set before AND after the main game.