As far as games go, Ninja Chicken 2 lands squarely in the realm of mediocrity. Nothing in the game will wow you with greatness, but it is crafted well enough to be a fun romp.
For comparisons sake, Ninja Chicken 2 is like a fixed, manual version of Plants vs. Zombies. Instead of building plants though, you are given a set number of cannons (either 1 or 6, depending on the game mode) to fend off the invading pigs that are coming to bust down your wall. All three game modes provide a different way of moving your cannon(s), but all have the simple goal of killing all the pigs on the screen. Once each wave is over, you can spend your collected money on short term weapon boosts, big one time use weapons, or wall repairs.
While killing the pigs is generally fun, the repetitive nature of the attacks becomes grating after a few waves. The problem is that there are only a handful of different attacking pig types and they only drop weapon boosts every so often. Ninja Chicken 2 is sorely lacking permanent weapon upgrades, as well as enough money per level to buy your own weapon upgrades. In its current form, you can buy huge amounts of money via in app purchase, but the game is entirely beatable without any extras. In all reality, the game would have to be harder, longer, have more upgrades/things to buy, and generally be more fun for me to even consider buying extra money.
There's really not an overly compelling reason to recommend Ninja Chicken 2 over any other game in the App Store, but I can say that it is well made, has pretty solid graphics, and has responsive controls. Compared to Kongzhong's first offering (Ninja Chicken), though, this one just seems a bit stale.