A few points.
Smokers (I don't smoke.......... cigarettes) don't usually defend their unhealthy habit with 'taste'. People smoke for the caffeine- like head rush it gives you. For the effect. So the chorus of the song struck me as kind of ridiculous, because the case is never being made about the taste.
Your character was also shown eating a burger, which is also unhealthy and 'sealing one's own fate'. I completely agree that smokers should keep their smoke out of other people's faces and lungs, but there are a lot of ways to kill yourself slowly. Smoking is simply one of them. So is pumping your body full of sat fats. Lots of stuff kills you.
Non-Smokers die, but there has yet to be a single case of tobacco related lung cancer in the case of a non smoker. Sure, there may be damage, but it isn't that deadly..... not more than keeping your cellphone next to you than while you sleep, or sitting down for 9 hours a day behind a computer.
On to the animation. It wasn't that great. It was very choppy, sloppy, and half-baked. The alligator, (supposed to be some kind of jerk I suppose) is never really elaborated upon except to simply be a foil for how much smoking sucks. Most of the movement seemed like either bad tweening or really choppy frame by frame. The backgrounds weren't comprehensive.
On to the Music. The song was good insofar as the message it conveyed was a socially correct one. A good message to be putting out there. That being said, the melody wasn't that engaging, the chorus was ridiculous and personally unappealing (lyrically and melodically), and the harsh acoustic guitar wasn't recorded with quality equipment.
I don't want to be a stickler, you put a lot of work into this, that much is quite clear. However, when you're on the front page of newgrounds, you are clearly up to the challenge of being critiqued.
-research your facts about smoking.... maybe get to know a few smokers
-take more time with your animating.... commit to having a lead singer animated or don't, the random appearances were jarring.
-invest in better recording equipment / use more than just an acoustic guitar. The song wasn't that pleasing. As a fellow songwriter, I can tell you that your chorus needed finessing. The rhythm was almost there, but broke down at the chorus.
Creative Message 8/10
Keep it up man.