Overall, Secret Files: Tunguska is a fairly enjoyable, if flawed, slave to convention.
Few games cover the spectrum between good (sometimes even excellent) and bad the way that Tunguska does. The opening cut scene is cinematically impressive, feeling much more like the opening to a movie than the introduction to an adventure game. Unfortunately, like many adventure games before it, and doubtless many to follow, the effort spent on the cinematics is little clue to the overall quality of the game.
That's not to say the rest of the game doesn't look good – in fact, the visuals are undoubtedly the best feature of the game. Every location looks excellent, and rendered in sufficient detail. Characters also look great, blend well into their surroundings, and move in natural, realistic ways. Cutscenes are superbly animated, though often a bit long and wordy. It's worth noting that downloading the 1.02 patch is an imperative; on some systems, unpatched games will reach an unplayable point due to a cinematics glitch, and the patch adds in an extra endgame movie. Because I never saw the ending without the patch, I don't know what was actually added, but I do know that the ending cutscene was one of the best parts of the game.
A game that looks this good might be expected to sound pretty decent, too. Here, too, Tunguska ranges from excellent to abysmal. The music is certainly very good, and used to great effect. Ambient sound is well balanced, and brings depth to locations, from chirping birds to screaming inmates. Unfortunately, the voice acting is simply absurd. Nina, the protagonist of the game, is your typical hot adventure babe, and looks like she could be one tough chick if put to the test. Unfortunately, she sounds like a 14 year old airhead, with a squeaky, often whiny voice, and some of the silliest dialog ever. At one point, she claims to have been a honeybee in a previous life, which would be fine if voiced with the expected sarcastic or playful tone, but she says it so earnestly that you can't help but laugh at the statement. The same problem plagues almost all of the dialog; the best dialog comes from a mysterious, ominous character in the custscenes (and during the ending cinematic that provides Dragnet-esque character follow-ups in perfect Joe Friday deadpan). The poor acting might be overlooked if there wasn't so much (and I mean, a lot, a lot, a lot) of dialog. Plenty of dialog is fine if it really advances the story or is integral to puzzle play, but I managed to finish the game by just barely skimming the text and clicking through the spoken portions.
Unfortunately, the most ridiculous fare that Tunguska has to offer comes in the form of ridiculous solutions to bizarre puzzles. More often than not, you'll come across solutions by accident, simply by experimenting with your inventory out of sheer desperation. You'll drape a flag over a sign, without any clue as to why, until you go inside and hear a truck crashing. You'll traipse around a Dublin pub trying to make a fish for a customer, for the sole reason of distracting the barkeeper. From figuring out how to make posters for someone just so they'll help you, to cruelly tricking someone into believing he's won the lotto, most puzzles and their solutions are so farfetched and senseless that you'll either end up turning to a walkthrough, or simply try every inventory combination you can just to see what works. The few set piece puzzles in the game, on the other hand, are painfully easy, and feel almost as if they were thrown in just to keep the puzzles from being strictly inventory-based. One nice feature about the game is the "search room" function, which briefly highlights all the hotspots and exits available in a room, reducing the need to pixel hunt (especially helpful considering the huge amount of detail in most screens).
That's not to say that Tunguska isn't actually fun. For all its faults, it's actually a fairly enjoyable game. The story is interesting enough, if a bit drawn out, and there are just enough twists to keep you guessing. The puzzle play may be bizarre, but they are at least creative. In the end, my favorite part of the game turned out to be the ending cinematic; it actually made me laugh (in a good way) a few times, and proved a rather satisfying end to a downright strange experience.
All in all, The Secret Files: Tunguska is a decent game that's great to look at and fairly fun to play. If you can ignore bad acting, and don't mind Sierra-style bizarre solutions, you'll probably find enough to enjoy in Tunguska to make it worth playing. At the very least, it can be fun making fun of the game as you play through it.