1. It knows what it is and acts accordingly.
Have you ever been to watch a film about cool things and then found out the director sneakily weaved a bunch of shit things into it? Things like 'themes' and 'twists'? So many times I've seen a preview that has blown my mind only to go and watch the film and find that the reason the preview was so great was because it didn't represent the finished product; which is a shit film full of 'themes' and 'twists' and 'social commentary'. Film studios should have to post disclaimers at the start of their previews if they're going to touch their work inappropriately in between the preview and release date.
Pacific Rim's preview promises one thing; epic battles between giant robots and colossal alien lifeforms with a loose emphasis on plot/conviction and a gaping wide opening for a ramped up sequel somewhere in the foreseeable future, and that's exactly what I got from the finished product plus heaps more.
2. It has everything, including a classic Japanese revenge story.
Pacific Rim's pre-apocalyptic setting is a great mechanism for selling widespread hopelessness and engaging it's audience for the mere fact that humans enjoy watching the world fall to shit (on screen) and fantasizing about they'd theoretically react to whatever it is causing the apocalypse. Just in case that wasn't enough, Guillermo Del Toro throws a good old-fashioned Japanese vengeance sub-plot in there, portrayed through the pint-sized technician/martial artist/whatever Mako Mori, whose shy and polite demeanor hardly masks her appetite for inter-species revenge.
Now, Japanese revenge normally always involves swords, right? Couple this with the fact that no average sized sword would be an effective means of exacting revenge in this particular case and it suddenly becomes very important that we move onto my next point.
3. Japanese sensibilities + Gargantuan Robot battles = Boat Sword.
Yes, Boat Sword. If you see one movie this year where a 300ft robot wields a freight ship like a lightweight Katana, make sure it's Pacific Rim. Seriously, there will never be anything better than Boat Sword in any of our lifespans.
There's another pretty cool sword in Pacific Rim, one that might have more of a correlation to the revenge theme than Boat Sword, but I mean....come on.....it's a fricken Boat Sword.
4. When a Kaiju screams, you hear it and when a Kaiju gets rocket-punched, the Kaiju definitely feels it and you can feel how it would feel as well.
What I'm saying is, the fight scenes are orchestrated with such passion that the audience has no choice but to be in the fight as well, or at least watching it comfortably from a safe distance. Every rocket punch connection, every Boat Sword (!) parry and every colossal suplex through every Hong Kong skyscraper will send shivers through your entire being and elicit feels that only a Kaiju/Jaeger battle can. Also, the rain is very rainy.
Imagine a film where Idris Elba walks around in pea-coats and dapper high-ranking military wear, barking orders at lowly Jaeger technicians, delivering inspirational anti-apocalypse speeches whilst protecting his adopted Japanese daughter from the harsh realities of long-term Kaiju resistance and acting as a mentor to the next generation of Earth defenders.
Congratulations, you have just imagined Pacific Rim.
6. It's Pacific Rim.
Seriously. Who watches a movie like this and reaches any sort of critical conclusion aside from "Well, that was DEFINITELY Pacific Rim!". Sure, the macho main character is all but devoid of genuine emotion, there's probably some cohesion/plot holes to be found (like every other movie ever) and there's a few slices of (liberally applied) cheese throughout the film's (immaculate) pacing, but when you're willing to sit through all that because you know that on either side a Category IV Kaiju is roaming around just waiting to feel the wrath of a Boat Sword, you know exactly where Pacific Rim's intentions lay and thus, it's beautiful, nuclear-powered vortex turbine heart.