Okay for those of you who watched the original series be prepared for things to be "very" different. F/SN was based on a game which had 3 possible situations the series did the 1st (with elements of the 2nd and 3rd situations thrown in), this does the 2nd and the pacing (because it is a film not a 24 episode series) is a lot faster and in many ways expects you to know most of the back story so it tends to just speed on ahead.
The film itself was well done and the story while having a few holes (read my comments above to why the holes appeared) worked well, especially since they had most of the original if not all the original voice cast return and used some of the same soundtrack too.
It might not be as engaging as the original series but if you let the series and the film stand apart as two different stories, you will find this film good fun to watch and an evening well spent.