Although I did not enjoy playing Fail-Safe, I had to give it a good rating for its very effective and innovative narrative voice. Jon Ingold is really a master of this and it shines brightly in this early game. In fact I think the brevity of the game really accentuated the tantalizing and creepy atmospheric effect of the narrative.
It would be a shame to elaborate further on the nature of this narrative voice, for it would ruin the experience of playing the game, and as the puzzles and plot are fairly unmentionable, this would seriously detract from the merits of the game.
However: Fail-Safe, by so exquisitely rendering its eerie atmosphere, produces a distinctly uncomfortable feeling; there is blood, you are trapped, it is an emergency. I would not recommend this game to anyone who is not fond of such scenarios, because the game is, from its first line to its last, so instantly and totally immersive.
In this way, its greatest strength can be its own shortcoming (for some players) -- the narrative method is so effective that I sincerely disliked the feeling of being immersed in the world of Fail-Safe, as it felt so very real and urgent and disturbing.