1. Introduction of the game:
Welcome to the thrilling world of Zombieville USA 2, the highly anticipated sequel where survival meets cartoon-style gore. This action-packed side-scroller infuses humor and horror as players blast their way through hordes of the undead. With improved graphics, dynamic gameplay, and a host of new features, Zombieville USA 2 takes the zombie apocalypse to a whole new level, combining strategy with fast-paced action to captivate both seasoned gamers and newcomers.

2. All characters and levels of the game:
Players can choose from a diverse roster of characters, each with unique abilities and upgradeable stats to suit different playstyles. From the shotgun-toting police officer to the katana-wielding ninja, the game offers a varied cast that adds replay value and strategic depth. Across numerous levels, players will fight back the undead in a variety of environments, ranging from desolate cities to eerie graveyards, each more challenging than the last.

3. What attracts users most to the game:
The game's appeal lies in its addictive combination of character customization, weapon upgrades, and cooperative gameplay. Players are drawn to the game's cartoonish yet detailed art style, the satisfying combat mechanics, and the engaging progression system that keeps the game fresh and exciting with each playthrough.

4. Why it is popular:
Zombieville USA 2's popularity stems from its accessible controls, comical graphics, and the sheer joy of mowing down wave after wave of zombies. The game strikes a perfect balance between simplicity and depth, ensuring that both casual players and hardcore gamers can find enjoyment and challenge in its midst.

5. The most difficult part of the game:
The difficulty of Zombieville USA 2 ramps up significantly as players progress, with the later levels presenting the most challenge. Here, players must balance resource management, quick reflexes, and strategic use of their character abilities to survive against overwhelming zombie waves and tough boss encounters.

6. Strengths and weaknesses of the game:
Strengths include the game's charming visual style, the satisfaction of character progression, and the addictive cycle of looting and upgrading. However, the game's weaknesses might include a potential for repetitive gameplay and a lack thereof in terms of storytelling or in-depth narrative components, which some players may seek.