First, let's get my biases out of the way, so that you can judge my comment accordingly. I am a Michael Cera fan. I am an indie movie fan, but not an aficionado. I wanted to see this movie. I'm a young guy who likes some romantic movies, but they have to be rather good. I didn't know anything about this movie aside from what the trailer tells me. I think that does it.
A lot of the comments on IMDb about this movie center around the format. I agree that the style is important to talk about, but not the only thing. The style is documentary, but with certain deviating aspects. It isn't Blair Witch Project; it has decent editing and lighting. The angle is natural, all from a guy or three carrying cameras. Certain scenes are done in paper cutouts in paper scenery and wires for movement. These are usually the scenes that they didn't catch on camera and are important to the plot. These scenes are really charming because of their scale and their construction.
The "acting" is also good. The most controversial aspect of this movie is the content, or the plot. Some think that this movie is either simply an observation of life or a movie about an observation of life. Either real or reel, some might say. I tend towards some middle ground. I think that this movie is a documentary about real life including a documentary about real life. There are staged things and things that look really genuine, so I think that it's more of an embellished real story. The cynic in me thinks that a lot of it is fake, but they did a really convincing job so I hope its all real.
If you are an optimist, this story will be really cute and lovable. If you believe it to be faked, it's a bad movie. That is why I think it is mostly genuine, if not completely. If this was produced in any really directed way, it would not have included some things in it that it did. But then again, they could have included it to make you think that. Whether you're paranoid about that sort of thing is beside the point. This movie feels very real. I know some of my dates were almost exactly like some in this movie. Charlyne is believable and so is Michael Cera.
Michael Cera plays a really cool guy with a cute awkward disposition. If you're a fan of Michael Cera, you'll recognize his characteristic style, but now I believe that style to be more of just how he is instead of an acting style. Regardless, he's endearing. Charlyne is also really lovable because she's funny and easily embarrassed. The two are quite genuine and work really well together because of their similar personalities.
Overall, a cute and lovable movie. The ending is unsatisfactory, but that's because there is no end that would fit the story and remain truthful to real life.