Firstly, forget the sci part of sci-fi. There is not even a pretense of real science in here. To be fair, there is also no attempt to call it science. Its a cheap monster-flick, and makes no effort to be anything else.
Now, this can only be appreciated as a comedy. It is that bad. From the rather strange monster to the annoying computer-voice to the blocky white-painter architecture of the lab, its the representation of its genre: Those films that are so bad you have to laugh.
Funniest moment... Alien Thing gets shot with the full output of a building-sized particle accelerator. Huge blue glow, sparks, and out steps a perfectly normal, unburnt human.