Hotel Dusk is from the same people who did Trace Memory / Another Code, and it slightly similar in gameplay. You hold your DS like if it was a book, and frankly, it FELT like some sort of interactive mystery novel!
And I do mean it's like an interactive novel! You'll spend 90% of the game reading, if it was an actual novel I bet it would be as a big as a Harry Potter novel... Only this is more awesome!
Adventure wise... It didn't actually feel like an adventure, but the story was so enthralling, that I didn't mind one bit, in fact I think this is the best mystery adventure I've played! Not counting those Gabriel Knight ones, but those are half horror half mystery, and this is pure mystery.
Like I said, it didn't feel like an adventure, the puzzles felt like where shoehorned it, just so it WOULD be and adventure and not an interactive novel, they didn't distract you because they weren't that challenging, and the "conversation puzzles" weren't that hard, since the only times when you could say something that could make the game end, the person you talk to will "flash", as a sign of warning to take care with your words.
Frankly I wouldn't mind if they did more games like this, you could take a good mystery novel, and give it this "interactive book" treatment, and I wouldn't mind "reading it" at all!
To sum it up, it's a mystery novel disguised a game, but it's a great story, well worth reading!
But this also mean I only have one game left to play for the trip to Bristol, Harvest Moon, and if it's anything like the prequels, it will last months!