Though short and not for everyone, Braid manages to excel as a game and as a form of art.
Let's go ahead and get this out of the way, Braid is beautiful. Every level is designed with a water color sort of feel to it, though with even greater colors. The range of emotions provoked simply by the art in the game is surprising large, ranging from light and cheerful grassy areas with sunshine, to darker levels with nighttime cityscapes in the background. The game is wonderful eye candy, and shatters the notion that games can't be artistic.
The soundtrack as well is incredibly fitting with the trippy world established in Braid. It plays heavily into stringed instruments and creates a soothing or dark atmosphere, depending on what is appropriate. Braid enjoys delving in duality like this. One minute you are in a bright snowy area, and the next you are in a bosses dark cave. This helps keep the game varied, as well as building upon themes in the story.
Braid's game play is also top notch. A lot of people may say it ripped off Mario, but ripped off isn't the right word. It is much better to say it pays homage to Mario. On it's basest level, Braid is very similar to Mario, in that it's 2d platforming elements, the base of the gameplay, borrows heavily from Mario. It even includes flags at level ends, and plants that come from pipes, and a search for a princess. These elements are obvious nods to Mario, and clearly intentional since jumping and climbing is similar to Mario as well. Don't get confused though, because Braid first and foremost is really a puzzle game, based on manipulation of the flow of time.
For example, say you really need to jump onto a specific enemy to get to a platform above, but by the time you reach him he has died, or you make a mistake in killing him. Simply rewind time, but don't just rewind a little, rewind as much as you want. In Braid you can rewind all the way to the beginning of the level if you want, and then start over again. This is how most of braid works, with no starting levels over or going back to any beginning, you simply reverse time and remedy any dying you may be doing. It seems like this may make Braid too easy, but Braid isn't really about succeeding at living anyway, it's about solving puzzles.
Puzzles in Braid are all time related, and become increasingly difficult and clever with each world. Additionally, new ways to manipulate time come into play, such as slowing down only certain areas, or using items unaffected by the manipulation of time. You may be surprised at how clever some of the puzzles are, and many of them are real brain teasers. Beyond the regular puzzles to collect pieces of a picture, there are many tidbits and secrets for those who want to dig deeper
Another area where Braid is seemingly similar is it's story. You are on a quest to save a princess. That is about where the similarities end. Braid chooses to tell it's story in a strange way. Before each set of levels are about 4-5 books. Each set before a level tells a different memory the main character Tim once had about her. This is no fairy tale happy love story though, immediately the story delves into a much darker theme, with the first set of books being about Tim regretting grave mistakes he made to drive the princess away. The storytelling is clever and poetic, and you definitely feel power behind the words as more is revealed about the past Tim and the princess hold. Without spoiling too much, lets just say that some of what is revealed near the ending might just blow your mind, or might not, depending on how deep you want the rabbit hole to go. If for some strange reason you actually want to forget about the story, that is also a viable option, as you can simply not read the books.
Braid isn't without it's flaws however. The most notable is that it is short. It took me about 3 hours to finish my first runthrough without looking up anything online, and then each one after is only going to take an hour. This might not have concerned anyone, except that the game costs about 15 dollars. In my opinion though, if Portal was worth 30 dollars, Braid is worth 15. The game is a gem, it bleeds entertainment, art, and intrigue, and missing out on it just for it's length isn't an excuse.
Another slightly more legitimate complaint is that the game probably isn't going to wow many people. Those who enjoy solving puzzles, reading between lines, and swimming in surprising amount of depth will be absolutely enthralled by Braid. However, for those who would rather take a story and game at face value, Braid is probably going to be just a pretty looking game with a great set of puzzles. And of course these people may also be the ones who draw the similarities to Mario games.
Minor nitpicks aside, Braid is absolutely fantastic. It is a game that oozes style and art, but doesn't pull a Bioshock by only being about making a great story. Braid also manages to be a fun and challenging time-based puzzle game, that will suck you in and keep you thinking long after you have sunk as much into the game as is fitting to your style.