The movie starts off with promise...
It's an alternate view of the same timeline (start of the invasion) as seen in the the 1st movie, Skyline.
It's good to see things from the perspective of the people on the ground in the heart of the city as opposed to being in the apartment complex. It even has the similar good feel of the initial movie.
The problems begin when they move to the inside of the alien ship. Things get silly and it loses its mystique. They show the actual aliens controlling the ship... then you have to believe that they could build complex technology with those cumbersome claw hands, etc... etc...
The fatal flaw that SciFi movies make all the time. Monster aliens verses believability.
It's like when you watch a serial killer thriller... and as soon as you find out who the serial killer is, it's no longer suspenseful.

Overall, it's an okay movie, but you need to turn your suspension of disbelief to maximum in the 2nd half of the movie.