I didn't end up watching trailers or playing demos of this game since I had immediately decided to put this game on my must-buy list. I wasn't disappointed. The trial and error gameplay actually works in context: you never know what your actions are going to do and sometimes you can make things WORSE. And usually the worse scenarios are pretty funny. When you discover something useful, usually a thought bubble will pop up with other character's opinions on your discovery, and if you run out of time, the characters will usually let you know what they think you should try without giving away the solution. I definitely preferred the hint system to the "flounder around showing evidence like an idiot" system that occurred in Ace Attorney when you weren't sure what to present and where. But because there is a puzzle element to the game, I think the game mechanics wear down after some time and the one additional power you get isn't really a significant change. I think the game ends at just the right time for you to not tire of the gameplay, and the story is definitely worth the time investment.
Visually, Ghost Trick really, really stands out. I really want to say that this game has the best graphics on the DS. The characters are simple and stylized, but the animations for the characters are as good, if not better, than blockbuster games on consoles. Sure the movements are pre-canned, but they're imbued with a life and energy that so many other games lack. I was genuinely surprised that every character, no matter how minor, was given so much attention and polish. This is a very cohesive world with charm to spare.
Also, the music is super catchy, with the same composer as Ace Attorney's original composer, Masakazu Sugimori. I made sure to have headphones so I'd never have to play this game in silence. The soundfont and sound effects he used were the same as the ones used for the Ace Attorney game, but the compositions themselves have more bounce. But despite the generally happier tones, when you run low on time to save someone, you can bet the music ramps up the tension tenfold.
All said, I agree with the 4 star rating. Ghost Trick is a must-play game, but the length is short and the replayability is not good. I think this game is better suited for a budget price, much like the Ace Attorney series.