The words 'interactive fiction' imply a story you can truly influence - that you're part of the process of telling the story. Unfortunately, few titles actually accomplish this. Even when the game contains multiple paths, you're still essentially playing through a detailed puzzle box. Blue Lacuna is an outstanding piece due to its true interactivity.
You, as the PC, have the ability to Wayfare - to travel between worlds and places by creating art. When called by another of your kind, you rush to the rescue - only to find yourself on a near-deserted island with a crazy old man and some very creepy trees. Who called you here? And what do they want with you?
This game goes far beyond multiple paths: you genuinely do shape the story. The characterisation of the PC is entirely up to you and you're able to act in almost any way you feel fits. In turn, your actions shape the environment, the outcomes of the story, and the attitudes of the one main NPC in ways that frankly boggle the mind. Progue is an incredible NPC; your behaviour towards him influences his towards you, as well as what encounters you will have. He can be your mortal enemy, love interest, or anything in between. No two playthroughs will be the same. Sadly, the game is so huge and time-consuming that it's difficult to live up to the near-unlimited replay potential.
The setting - the island of Lacuna - is a character in itself. Complete with succinct but vivid descriptions, day-night and weather cycles, random environmental events and an expansive but intuitive map, it's the most detailed setting I've ever seen in a work of IF. Even on third and fourth playthroughs, I'm still discovering new treasures hidden away. Exploring Lacuna even without a plot to drive you would be well worth the effort. Speaking of the plot, it's one of the few things that don't replay so well. The main events of the plot (particularly the (Spoiler - click to show)dream sequences) are less adaptable than the rest of the game, so even the most haunting parts grow dry and familiar after you've read them once or twice.
Aside from the story itself, Blue Lacuna breaks ground in other ways. You may select between story and puzzle modes; this adds to the re-playability, and means the game will appeal to both fans of narrative (like me) and those who like a challenge. I loved this touch and wish more games would offer it. While not exactly a new idea, the (optional) compass-free movement commands heightened the realism and made it feel like you really were exploring the environment instead of a game map. (Spoiler - click to show)The backstage commands were a brilliant touch; they made it way easier to find new endings and to otherwise mess around with the game environment, which is always fun.
Unfortunately, with great interactivity comes great complexity, and with great complexity comes great bugginess. (Is that a word?) On my first playthrough, an essential plot event (the (Spoiler - click to show)tsunami, if you're wondering) never triggered and the game was rendered unwinnable. Though nothing that bad ever happened again, the interpreter kept crashing during one of the conversations and there were way too many bugs and minor inconsistencies to count. I understand that the huge scope of the game makes it impossible to debug completely, but I had so many issues dodging bugs it's enough to lower the game one star in my estimation.
Blue Lacuna is a groundbreaking game that is likely to take an important place in the history of IF. If you enjoy immersive games that reward persistence and patience, then I would definitely recommend giving it a play.