Sure, this is a crappy B-movie. It's full of bad acting, terrible writing, and has the worst rubber monsters I've ever seen. But it's a pretty good crappy B-movie.
Directed with flair by Kinji Fukasaku (Battle Royal, Black Lizard, Message From Space), this has a lot of things I'm a total sucker for: miniature effects, swingin' chicks in miniskirts, and a sweet garage-psyche title song.
But by anyone's measure The Green Slime is quite a bit of dumb fun. It sets up a nice love triangle between the leads, establishes the scenario with some kitchy space station and outer space sets, and once the action kicks in it's a full board disaster movie with lasers and screaming and the aforementioned ridiculous rubber monsters.
On a side note, I'm eating saag right now. It looks like the green slime in the movie. Not sure what that means.