Definitely a good game, but with an obvious flaw..
This is a great game, easy to use, fun to play, but the fact that you don't even mention that it is just a demo in the description is a flaw. I am the kind of person who would buy this, but for $15???? Excuse me this game in total at 10 levels would have around 2-3 hours of game time. I would gladly pay $5, even $10, but come on it is not 3D, it doesn't have 1 million levels, it's not particularly amazing, I will repeat IT IS FUN. But at $15 and a demo that last 15 minutes, this is kind of sad. This is Newgrounds, if you want to put up a demo, give us something to actually play, seeing as how almost every game on here is completely free.
Now my real review:
I enjoyed this game, great concept, nice explosions, good sounds, and the utter combinations are astounding. I like how you can build your war-train. I like that if your cart is detached that it can still fire. The only thing that I don't like, besides the above rant, is the fact that you can't fire and add a cart at the same time. It has happened to me where in the time it takes my train to stop there are enemies that come on the screen and I can't fire, also if you could exit drop mode that would be nice. As I said great game, but we get into it and you end the demo, maybe a downloadable demo/full version would be cool, timed use of a few hours..... Ehh, but that's your problem.