This narrows it down:

The word "crapanese" comes to mind, if you're not a fan of the rubber-suit-monster genre. I don't mind the good ones, but when they introduce kids, it's another matter. Kids in a spaceship, for that matter:

They found the ship in a field, got in, and blasted off for a duplicate earth that circles a duplicate sun on the other side of our sun. Yeah, we would have never figured out that second-star deal. The kids are in peril, but lucky for them an enormous spacefaring turtle comes along:

Gamera! Friend to children!

Once they get on the alternate earth, they meet an enormous, hungover, knife-headed creature . . .

. . . who fights, and defeats, a windshield ice-scraper covered with aluminum foil . . .

There are cape-wearing spacebabes who show up to pad out the plot between battles. The dialogue is dubbed, of course; the kids are graduates of the school of Affirmative Exposition, which means that one says "that's Gamera" and the other says "you bet it is."

It all comes down to ginsu-noggin vs. space turtle,

All you need to know can be learned in these clips.

I think this movie may be aimed primarily at children.