Assessment: loved it. I have a thing for well done quirk. Here are some thoughts:
1. Mark Ruffalo and Rachel Weisz in the same movie! Actor/tress crush alert! And Adrien Brody! And I'm now officially in love with Rinko Kikuchi in her mostly silent role as the explosives expert to the brothers. But seriously, every one shines in this movie with the material they're given. No one is less than charming, and everyone gets some very funny moments.
In this case, Stephen (Mark Ruffalo) is doing most of the charming work, while Bloom (Adrien Brody) gets serious about quitting the conning biz. Also, hats.
2. Fun soundtrack by Nathan Johnson that combines ragtime with the occasional electric guitar or organ and the occasional outburst of Middle Easternish melody. It kept things sexy (in an innocent sort of way), light, and olde tyme feeling, not to mention magical.
3. Very deliberate set designs and costuming that make sense in the the film's world of contrived conning situations. Plus, it doesn't overshadow the emotion of the scenes. It's like Wes Anderson, except I care*.
The color schemes are pretty muted, mostly consisting of white and black with the occasional splash of color. Love Rinko's suit in this scene. Also, shuffle board.
4. The Brothers Bloom manages to be entertaining the whole way through with moments that suprised me. It's a pretty straight forward film, but I got so caught up in it I was still anticipating what happens next.
5. Whimsical. Delightful. Also, funny. But mostly whimsical.
Did I mention adorable? Look at that budding relationship between Penelope (Rachel Weisz) and Bloom. Also, their outfits match (hard to see, but his vest and tie are the same green as her sweater).
6. The writer/director Rian Johnson: I'm going to keep an eye out for this guy. I like his style, first in Brick and now The Brothers Bloom.
7. See it if you can. By some fluke it came to the dollar theater in my town. It's worth seeking out.
*This comment is mostly aimed at The Life Aquatic which is like an explosion of pretty things set to a terrible/slow story about unlikable people. On the other hand, I really like The Royal Tenenbaums.