I thought it was very enjoyable. As a fan of Kirby's techno-mythology, I loved seeing more Asgard and the nine realms. Couldn't get enough of that, the Dark World looked cool. Fight scenes were cool, but after Man Of Steel, every fight scene feels small.
Also, there was a bit too much comedy for me. Too often it undercut the seriousness of the movie and threat, making the movie a borderline comedy. I thought the first phase movies had just the right type and amount of humor. Here it had the feel of "hey, remember that thing audiences liked in the first movie? Yeah, let's do a shit ton more of it!" It started out fine, but after awhile it got annoying.
Otherwise, I enjoyed seeing Thor's world expanded and would love to see some of Thor's cosmic epics brought to the screen.
While I've been more of a DC guy for the last two decades (stopped reading Marvel around 91-92), Marvel's "cosmic" stuff is way beyond anything DC has been able to do in any way, shape, or form. Skrulls, Recorders, Watchers, Galactus, Shaper Of Worlds, Thanos and the Titans, Celestials, Collector, Gardener, Stranger, etc.
And Starlin's run on Adam Warlock (where he turns Adam Warlock into an Elric character, complete with soul sucker and doomed fate) is one of my all time favorite runs ever. I saw the cocoon and thought "Warlock?" I don't know if he's in the current incarnation of Guardians Of The Galaxy, since I'm not familiar with that team. I'm more familiar with the Vance Astro group from the future who fights the Badoon.