Now, to try and give this cartoon a serious review would be pointless. I would no more do that than I would give a serious review to a 'Looney Tunes' or 'Tom and Jerry' cartoon. This is not high art; it is intended to be brainless fun. So the question is, does it succeed as brainless fun?
Well, as to whether or not it would be classified as "brainless", let's just say that no one's mental faculties are going to be particularly taxed in trying to understand the cartoon's plot. I mean, really we're in 'Looney Tunes' territory here. It's not as mindless as Wile E. Coyote making endless attempts to catch the Road Runner, but this is a simple story, a variation on many that we've seen before. It begins with a man named Reilly answering a personal ad for a young woman who is looking for a relationship with a fellow cat-lover. Eventually, a bunch of cats wind up having a party in his bachelor pad while he is out on his date. I won't say any more about the plot, but let me just add that this cartoon follows the familiar theme of a character watching as events around him spiral out of his control, a theme that generally causes me to cringe rather than laugh. I found 'The Cat in the Hat' difficult to read and 'The Money Pit' difficult to watch for the same reason; I have never enjoyed watching people's lives and/or property slowly ruined.
And now for the second part of the question is it fun? Well, since the story is treading no new ground, the interest is obviously going to have to be in the details. For instance, take the art direction. It's very much in a 90's Ren and Stimpyish style, and in fact several of the animators also worked on that cartoon. It's a style that many people apparently like. Unfortunately, the effect on me is a little strange and unnerving. I think it's mainly something about the eyes they're kind of freaky.
Then there is the humor. Now, this really isn't a "detail" at all, but the actual crux of what makes this kind of cartoon a hit or a miss. 'Looney Tunes' and 'Tom and Jerry' were definitely nice to look at in the art department, but art was not what defined them. What defined them was the variety and creativity of ways in which the characters could make us laugh by crushing, burning, and pulverizing one another. And ultimately this is why I am only able to give 'Buy One, Get One Free' an "average" review because it really didn't make me laugh all that much. Okay, I admit I did find it amusing when Reilly lost his cool at the end; the humor at that point contained the bizarreness that made 'Ren and Stimpy' so popular. But other than that, there really weren't all that many jokes, and what jokes there were didn't do a whole lot for me. In fact, some of them were slightly disturbing. For a cartoon to be brainless fun it really needs to be fun-NY, and I just didn't find enough "NY" in this one. I suggest watching some of the other episodes in the 'What a Cartoon' series there were definitely funnier ones than this, and some that eventually became their own series.
Okay, I think I just gave this cartoon a way longer and more serious review than was necessary. I mean, it's only 7 minutes long for crying out loud. In the time it took you to read this, you could have just watched the cartoon on YouTube and judged it for yourself.