This is a bad game, a two-star game on its own merits, and then gets dinged a star for problematic cultural assumptions all over the place. It is such a phoned-in, half-assed, conventional, unoriginal, artless game.
It's pretty fun, but you have a serious balance problem: ninjas. Ninjas are not fun, and they're the only actually difficult enemy in the game. As a result, the game lacks serious decision-making because the only enemy you really have to care about is ninjas. The answer to everything else is "more." More towers/upgrades/whatever.
Terrible UI/UX choices - dog size, hitboxes, how much does it take to get bigger, speed, all sorts of things. Go play Amorphous for a much better game based on the same mechanic. Unless you really hate dogs.
Great premise, but major implementation flaws. Reliable information about the game state isn't presented to the player (e.g. range of weapons), both through oversight and through bug (e.g. it's pretty frequent for the mouseover status for a plane to just Not Work). Also, a gradual volume-control slider is much more useful than on/off.
Massive problems with controls - if the controls worked right, it'd be merely difficult, in a good way. Right now, it's just frustrating because it feels like it doesn't reward jumping through the hoops.
Good premise, but poor difficulty scaling. Most of your par-2s should be par-1s, about half of your par-1s should be par-2s, and your par-3 should definitely be a par-2. Also you've set the coefficient of friction just a smidge too high.
I like this game's sense of humor - it'd be interesting to see more comments from the animals, but I can see how it might clutter things. ArmorGames has a good eye for quality.