There are two types of movies out there. Movies that are intended to make you think, and movies that are pure fluff of various types.
Pacific Rim is most certainly the latter. The movie is about Voltron vs. Giant Monsters. There is nothing about this that is supposed to be thoughtful or intelligent.
And boy is it fun.
The back story: monster alien thingies are coming through a dimensional portal (The Rift) beneath the ocean. Their intent? DEVOUR THE WORLD.
Picture from TFWiki
After getting kicked around and generally eaten for some time, humanity makes Giant Robots to fight back. Naturally. The robots in question are called Jaegers (and yes, they do have bombs), and are piloted by two people via a telepathic linky thingy because one person cannot handle the stress of operating the entire machine alone. Our hero, Raleigh Becket, was a pilot along with his brother (the pilots must share a close bond), but his brother was killed, leaving him to be Retired for Ten Minutes. However, with the news that there may be another wave of Kaijus, Raleigh is yanked from his retirement to find a new partner and help fight off the next attack.
This is the definition of a popcorn movie. The characters are decently well-drawn, the action is excellent (although sometimes implausible-that said, they gave Raleigh’s Jaeger an Optimus Prime sword, and you just know they did that on purpose), and it does indeed get a bit emotional in some parts. Refreshingly, the females are not relegated to being “the girlfriend” or “the ugly scientist lady”. Raleigh does have a love interest, but that fact doesn’t overwhelm their individual character arcs.
Even the minor characters, while not exactly three dimensional, are still fairly unique and interesting. So, yes, while some things get a bit silly, overall it’s a very enjoyable movie.