ST:TWOK did it all by word of mouth and fantastic writing, directing, and filmcraft.
Not really - STII was VERY hyped leading up to its release (and I was there in 1982 and saw it twice on opening day) - and the fact Spock dies was known (just not when in the film and they had the mis-direction of having Spock 'die' in the opening simulator scene - so many figured that was the 'death' leaked to fans); BUT, the fact was, it was just MUCH more enjoyable ST film than TMP was - and Star Trek fans were so happy about that we were indeed willing to IGNORE the GLARING plotholes and inconsistencies, such as:
1) The Reliant crew (Chekov in particular) not noticing that Ceti Alpha V exploded and other planet's orbits in the system were altered. (Of course if he's written competently, we have no film.)
2) The fact that (again by the Reliant's scans) the altered Ceti Alpha V was shown to be uninhabitable (with a toxic atmosphere; and even Terell and Chekov beam down in EVA gear) - YET - Khan and his people seem to survive in the open just using masks - and are able to trake long walk from therre containers (for what purpose who knows, buts it's the entire reason Terell and Chekov can check out the completely empty cargo containers.)
3) The fact that Chekov WASN'T a part of the Enterprise crew back when the events of "Space Seed"
took place -- yet Kahn says to him, "I never forget a face!" (and sorry the fan rationalizations don't wash as there was a line in Season 2 TOS stating Chekov was 'recently transferred to the ship.'
I also have an issue with Kahn being described by Spock (and depicted in the film) as 'inexperienced (in a military sense) and showing "two-dimensional thinking". Why? Remember his background as stated in "Space Seed"
- Kahn was one of the most militarily successful tyrants that conquered most of Asia before they were stopped <--- You don't do that without being a shrewd military leader; and any successful ground or air campaign would require three-dimensional thinking.
Again, NONE of the above prevented the film from being very entertaining; but, overall, nothing really stands out as overly exceptional with regard to the writing, directing or 'filmcraft'.
And I bring that up because as an old Star Trek fan (watching first run since 1969) - I honestly found Star Trek: Into Darkness
equally as enjoyable and entertaining; and honestly, (depending on my mood) it's either in a tie with, or ahead of Star Trek II: TWoK
as my overall favorite Star Trek feature film.