I did not really get very much out of this, to be honest. Our villain has a precosmic power source but he can use it to destroy a planet only if he first uses conventional weapons to fight his way past local defenses and down onto the planetary surface? And I am not clear how our guys stopped it happening, either.
So this happens elsewhere in the galaxy while Thor comes from Asgard and the Avengers assemble on Earth? I didn't see as much connection with the Marvel Movieverse as I expected but maybe I missed it? There is Thanos, of course. Maybe that's it? I didn't understand the post-credits scene or the reference to Howard the Duck.
I think that the Marvel Comics Captain Marvel was a man of the Kree? But he doesn't have to be mentioned here, of course.