Surprisingly fun for such a tie-in game.
I like how they have the plot point about getting past alligators by making them laugh, then later on you just get alligator enemies that you kill to get past.
Quite short and easy, but that's better than short and extremely hard and unfair and hellish, like the Garfield Gets Real game. It also beats Gets Real by having some really nice looking sprites (compared to (possibly appropriately) ugly 3D models).
I wish they hadn't cancelled the Pet Force game. It's safe to say it wouldn't have been incredible, but it could've been interesting.

Severely underappreciated in the West.
At the start, the gameplay is really fun, some of the best I've played from a NES game. But as the difficulty increases, it becomes infinitely more annoying to play. On the first few stages, the infinite continues (and no intralevel checkpoints) worked really nicely, then it felt like actually it would be nice to have a checkpoint at each door, and then it felt like there was nothing that could be done to make it fair. Though I did use save states, especially later on, so I don't know exactly what it's like without them.
The "Garfield" elements here are almost non-existent, other than the presence of characters (and some vague thematic similarities like it taking place in locations including a house, plus eternal suffering). Characters exhibit no familiar traits so they still don't even contribute much there.
It seems too obvious to be a glitch (though reasonably it must be?) but the fish collectable is quite useful. Usually, it detracts health, but if it would be enough to kill you, it instead completely fills the health bar. And it's fairly doable to use or exploit this throughout (even easier if you use save states). It adds an interesting element where if your health gets too low, it might be most efficient to get it low enough, and then search out a fish bone to fill it up again.
And it's elements like this that really make gameplay interesting. Being able to look around for items adds some interesting survival elements, where you can choose to aim to fill up on health / ammo, or you can try and rush on before more enemies spawn. The multiple weapon types work well too, and it's nice cycling through them quickly (compared to something like the Mega Man pause interface). It's nothing too complicated, but its simplicity works in its favour.
I think it controls nicely too, and if the enemies were more forgiving then it could've been a really nice game.
The difficulty really brings the whole thing down significantly though.
Also I liked the progression from "knife throwing boss" to "apple throwing boss" to "knife throwing boss" again.