So here's your couple-years-too-late review.
I'm not a big movie goer, so I usually end up catching things on DVD long after they've been out. I also avoid Marvel Universe movies like an AIDS-raddled ebola-carrying plague rat because I loathe what's become of Marvel over the last 25 years.
So I was surprised to find myself basically enjoying 'Guardians of the Galaxy'. It's predictable, annoying scenes meant to be seen in 3D that are pointless padding in 2D are annoying, and seeing it on the big screen would have left me with motion sickness and/or a headache (Speed Racer was the worst offender -- I barely managed it on the small screen and had to leave the room during the final race sequence), but it's a fun roller coaster ride with good snappy dialogue.
It ain't high art, but it doesn't pretend to be -- there are few things worse than FX porn that wants to be taken seriously, and GotG not only avoids that trap, it avoids being in the same continent as that trap.