A few thoughts: Of all the wacky, ridiculous Godzilla movies to come from the '70s, this just might be the weirdest. With random animated sequences, a bizarre giant lumpy mutant tadpole monster with googly red eyes, and another child-friendly Godzilla from the era that tried to turn the king of monsters into an adorable martial artist, it's really hard to watch this movie and take it even remotely seriously. Oh, and did I mention it started off with a James Bond-like title sequence? Because it did. While this still stands above several other Godzilla movies, it's overall not the most entertaining giant monster movie out there. The fight scenes are pretty dull, and with the exception of Godzilla using his breath to fly through the air (look below for an image of that bit of cinematic genius), there aren't enough silly moments to make you laugh as much as you will during something like Godzilla Vs. Megalon or King Kong Escapes. It was a weird point in time for Godzilla, and this is a great example of that, even if it isn't very good.
Who would I recommend it to? No one who isn't already a pretty big fan of Godzilla, though it might be interesting to plug this in for someone who doesn't know anything about the craziness of '60s-'70s kaiju movies just to watch their reactions.