By far the most fun Star Trek film I've watched up until now. Just the premise alone; Going back in time to the present (well at least the 80's) to rescue two humpback whales and bring them to the future (present to Star Trek time... confused yet?).
Just the collision of 23rd and 19th centuries is enough to make a good premise, but the characters acting off each other so naturally and the sense that they are having a good time makes the viewing experience all that much richer. It's always more fun when actors are genuinely having fun.
While not as "epic" as Star Trek II: The Wrath of Khan, it is definitely a more complete experience. It has a solid start, middle and conclusion, that doesn't feel labored and slow at any point in time. You are constantly wondering what's going to happen next.
VFX and sound take huge leaps from Star Trek III. They are very impressive for the time and the prop design around the ships is significantly better than previous versions.
Standout performances from Shatner, Nemoy, Doohan, Koenig and pretty much the whole cast make this film a real adventure. Nemoy does magnificently as director, a very well rounded performance from everyone.
Doohan using an 80's computer and giving some guy the formula for "transparent aluminum" with a few simple keystrokes is hilariously amazing. "just let me push these three buttons and voila, the entire formula and manufacturing process in a jiffy for yes, you guessed it, transparent aluminum... HAAAHAHAHAHAHA!
Another hilarious moment is the crew's fabled encounter with "money". It makes you wish you lived in a world where money is not necessary and people just took what they needed. Soviet hard handed communism aside, they were on to something here.
The other classic scene is with Koenig being captured as a Soviet mentally handicapped spy. Too good, just too good...
This film reminds us about what Star Trek is all about: Adventure!