The Expendables 2 has more explosions, guns, and blood than its predecessor. It seems that with time, The Expendables franchise goes back further into the 1980's.
With so many action stars in the film (Sylvester Stallone, Bruce Willis, Arnold Schwarzenegger, Jason Statham, Dolph Lungdren, Terry Crews, Liam Hemsworth, Chuck Norris, Jean Claude Van Damme), you can forget about character development in the film-- with the exception of Stallone, Statham, Lungdren, and Crews, the rest of the cast have very few screentime and I never get the chance to know the characters better. I also have to mention that the addition of Nan Yu as the sole female Expendable was a waste of time-- she was just awful.
That said, the film sticks to its guns (literally) and just seems to be satisfied to be a highlight reel of action movies past. I personally thought it the movie was going towards the Scary Movie zone, but it was pretty much saved by the climactic finale.
The Expendables 2 is a win for the classic action genre-- high enjoyment from action, but not a lot more.