Earnest from Joystiq wrote review of I: FL. He says that the story now is far fuperior to the plot in Infamous: Second Son. With more complex storyline, believable character with traumatic backstory.
Sucker Punch developers made a fantastic job identifying what were the best gameplay aspects of Second Son and used just them and stripped the less fun parts. There is again an extensive skill tree and even more intuitive.
But despite all of this it is hard to recommend I: FL to anyone but the most die-hard series fans. The game is simply too short. He was able to finish the single-player campaign in 3 hours which is practically nothing.
So it is a good game but not worth your money.