First of all, I liked this movie the most of movies that came out this year (better than Mad Max and far better than Jurassic World).
The action scenes were great but the plot fell flat because I wasn't captured by the forced melodramatic juxtapositions by Han vs. Ren and Luke vs. Rey. We see them meet for the first time and we're supposed to induct all nuances of their relationship by counting the seconds of silent scenes with misty eyes?
There wasn't the same veneer of ignorance from Rey and Finn to Han that Luke and Han had towards Obi Wan in the New Hope. The new characters don't seem driven by their own motivations but more like they are reacting to the destinies of the characters in the past films and even rehashing their errors (Kessel Run is 14 parsecs?).
BB-8 was not a satisfying comic relief and reminded me of the clumsy pod racing pit crew from Phantom Menace. C3PO and R2D2 had the best dynamic of all characters in the original trilogy and I wonder if it will work with a third wheel?
I'm guessing that Po fired a ion or plasma blaster bolt in the beginning that was frozen by Ren because why wouldn't he just deflect a laser? I really dislike the replacement of lasers with the plasma particles or whatever JJ agreed on for Ren's lightsaber and the Starkiller cannon because Star Wars has always been the definitive pew-pew and capitol ship movies.