The effects are absolutely terrible. If your budget can't afford big, realistic CGI, don't try to put in loads of it. I'm usually fine with lots of effects, but this looks like a drunk spent too much time in After Effects.
Skyline also has the worst ending I have ever seen in my life. The film just stops as soon as it gets going. There is no beginning, middle, or end. It seems like they ran out of money half way through or something.
This film is so bad, in fact, that it's funny. Therefore, I have to recommend it, if only just because it's so crap.