This was a groundbreaking film when it was released in 1956. It was the first sci-fi film set entirely away from Earth, and the first to feature an anthropomorphic robot as a character. So while the film may have been “important,” it’s difficult to say that it’s any good. While cribbing plotlines and themes from The Tempest, it’s hard to even take that ambition at face value, as most “lost in space” films tend to borrow heavily from the seminal work.
The biggest parallel here is that like The Tempest, Forbidden Planet spotlights a land under control of one man, seemingly through magic. The biggest difference is Forbidden Planet features a robot named Robbie.
Gnomeo features some strict adherence to its source material, save for the fact that the story is a forbidden love between two garden gnomes. In fact, they even reside in lawns belonging to families named Montague and Capulet, so no “inspired by” crap. This is the real deal.
Unfortunately, Gnomeo and Juliet borrows a page from the Shrek handbook and serves to be a little too self-aware to be taken seriously. Also, the film ends with (GNOMEO AND JULIET SPOILER AHEAD! WHICH IS THE WORST KIND OF SPOILER!) the two getting married on a lawnmower.
You’re just delaying the inevitable, producers. Kids gotta grow up sometime.