Great game, especially when compared to the first one. The mechanics are changed up, you instead have to capture "Dark Badges" and destroy all the towers in any given level to beat it. There's all the monsters you originally encountered from the first game, plus the red dragon - which is a step up from the green dragon - and the blood bat cave. The art style is much different, and looks a lot better. In the game, there's three different regions on the island you're trying to claim, a foresty region, a snowy region, and a volcnao region, each one has their own unique towers walls, projectiles, and overall look. In addition, there's two different tracks for each of these regions, which helps a lot in making sure you don't hear the same song over and over again while you're making your way through the 30 levels.
Overall, if you liked the first game, or prefer a nice, casual game in a fantasy setting, I definitely recommend purchasing this game, especially given the price.