Despite being a little too by-the-book and repetitive,"Infinetly Polar Bear" is a pleasing piece of narrative that succeeds thanks to a brilliant portrayal and definition of characters.
As stated above the film isn't that fascinating or riveting of a drama. It hits the same note again and again and does not stray away from it almost anytime. It is generally predictable and the dramatic texture isn't as intense as it wants to be,it kind of hits you very light. Moreover there are situations that are overplayed a little too much in the beginning which gave the movie a hard time at getting started and being believable, yet fortunately it picked up immediately as soon as these couple of scenes ended. So to sum it up, it simply doesn't give the necessary gravitas and intensity (both comedic and dramatic) to the situation for it to be as riveting as a drama as it could have as it could have been and I should add that I think that the cinematography partially contributed to this: it doesn't have enough style or distinction for it to stick out, leaving it in super generic dramatic territory and palette and it has a variety of camera movements that get distracting and aren't integrated well enough in the story. It could have really sparked had their been some distinctive look and approach in my opinion.
Despite all of negatives above, this movie really succeeds in making you care about the characters, sticking with them and ultimately giving you a true emotional link. That is undebatable thanks to very good work from both Saldana and Ruffalo and especially the two girls playing their daughters. But even more than that I believe that in the end it is the script that makes you really care because of how well it defines characters, situations and overall story arch. There maybe not enough originality in storytelling or some non-clarity in the bipolar aspect of the film, but man do the characters stick out and make for a pleasant view and journey, culminating in a finale that got me more than I imagined.