It's hard to say without ruining some of the plot..
I went in without any expectations and didn't really know much about it, just took a risk and I really liked it. It's pretty good with a hard examination of human traits and characters. The same author wrote "The Beach" which was made into a movie a while ago, starring Leo DiCaprio. If you like that you'd like this. Although, even if you don't like "The Beach" I think there is more to Ex Machina.
There aren't many characters, just the two male actors, a female robot and the CEO's assistant that does not speak English (she's Japanese), or much at all. So that could be boring for some, but I think it is strong in dialogue and character development. Oh, and the CEO's assistant is much nicer to look at than Will Farrell's yewt.