It's funny when reading people talking about this show, they are so angry and hateful at how much they dislike. It's almost like they take it personally.
I have no hate for this show. I think it's fun, mindless entertainment. I preferred it over shows like Alf, which I think is a good comparison, since he was a non-human character lead as well. Most of the jokes on Small Wonder are insult jokes. The special effects, I think, were done deliberately to look silly. It's like the show was done as a parody of sitcoms in general.
4 seasons is a long time for a 'bad show' to be on. If nobody was watching, then it wouldn't have last one season, but clearly there was enough interest to keep it going. That's no small wonder!
Review of Small Wonder
