I understand how many people who aren't familiar with the Ace Attorney franchise could watch this movie and be utterly confused and weirded out. However, if you have played the games (or just the first one), I think you will enjoy this film immensely, as I did.
Ace Attorney is a movie about a young lawyer named Phoenix Wright who, after the death of his mentor, must unravel a conspiracy that stretches back to a murder that took place over a decade ago. The characters are quirky, the story is insane, and the references to the franchise are in great abundance. It's not supposed to be realistic.
Here is why it is such a good adaption. The film took liberties with the story in order to condense it down into a 2 hour movie, but they did so effectively and kept the spirit of the games alive. Because of the differences in scenes and dialogue (while keeping the same core story), fans of the games can watch it and still be enthralled, despite knowing the outcome. And the movie is hilarious. As I said before, they make a ton of references to cases they do not showcase specifically in the film. Throwing confetti out of a garbage bag. The appearance of the Blue Badger. Everyone in the courtroom falling over from the sheer force produced in Phoenix's "Objection!" These iconic aspects of the game have been creatively implemented into the movie.
The acting is over-exagerrated, but to me at least, that made the film even funnier. Honestly, the casting, costumes, and make up effectively bring the characters to life. You recognize them instantly, and their weird mannerisms and personalities are amazingly written (save for maybe Maya, who seems a bit too serious in this movie compared to the game).
It's a fun ride from beginning to end for fans. If you haven't played the games, I don't know what to say. Buy yourself a DS and get to it.