CHRIS PRATT stars again in “Guardians of the Galaxy, Vol. 2.”

By Jim Tortolano

The key to real success, sometimes, is knowing when to stop. “Guardians of the Galaxy, Vol. 2,” the sequel to the wildly successful first film about a bunch of space misfits battling evil to a disco soundtrack works well for about the first hour and a half.

But the big battle scene at the end is not so much a cinematic climax as it is CGI excess and you find yourself glancing at your watch, wondering how much more of this repetitive explosions and light-show overflow you have to suffer through.

That’s a shame, really, because this “Guardians” is full of humor, gorgeous images, interesting plot twists and – of course – some great hum-along tunes for the Baby Boomers in the audience.

The film, again, stars Chris Pratt as the self-styled “Star Lord,” an interstellar orphan castaway who has gathered around him a motley crew of other oddballs, including a talking tree, a much-too-verbal raccoon, a hot green-skinned companion and more.

As in the first film, the plot is not as important as the fun, and if the buckles in this swashbuckler aren’t always very snug, is at making audiences grin. But here’s the story: while on another absurd mission, Pratt’s character discovers that his father is actually a self-created god named Ego, portrayed by Kurt Russell. Ego starts out as a benevolent figure but … well, you’ll see.

Pratt, as usual, carries it off with casual aplomb, and Russell sells it well, too. The show’s real star is Rocket Raccoon, voiced by Bradley Cooper, who veers between being endearing and irritating.

If you’re looking for “Citizen Kane” in a starship, this isn’t it. If you want some popcorn and a fun almost-summer ride with cool tunes, you’ve found it. Just be prepared to replace your grin with a yawn over the final 45 minutes or so.

“Guardians of the Galaxy, Vol. 2” is rated PG-13 for violence, intensity and some bathroom humor.