Cool Game!
The first thing you'll probably notice is the style. It is very stylish in film noir sense. Cool sketchy artwork defines the characters, and the animations are very good and subtle. It works really well, and it adds a lot of emotion to the characters.
Next, the story. It is decent, and not too over-the-top. It is the kind of story that you want to solve. You play Kyle Hyde, a former cop who quit the force after shooting his traitor partner. Kyle belives he is still alive, and has been searching for him. Hyde now a salesman, and is sent to Hotel Dusk by his boss to do something. While there, he senses this might be when he learns what happened to his partner after he shot him.
The game plays well too. There is a lot of (extremely well-written) text, where you learn about the story and get clues. While you aren't talking to anyone, you can move around and look at things in the hotel, where you gather clues and solve puzzles, and otherwise advance the story. The pacing is very slow, which might put some people off. But, personally, I like the pacing. It's all a matter of opinion.
Overall, the game is great. It's an easy game to pick up and play, has an engrossing story with very well developed characters, and intuitive gameplay. There are several endings and paths to take depending on how you react to people, which adds some replayability to the game. I highly recommend Hotel Dusk!