1. Introduction of the game:
Prepare for a blend of real-time strategy and action RPG like no other with "Heroes and Castles 2." In this epic sequel, you step into a vast fantasy world where you not only lead your hero into battle but also summon entire armies to fight by your side. Defend your castle against oncoming hordes of orcs, goblins, and other nefarious creatures, all while exploring mysterious lands, looting for treasure, and expanding your kingdom's reach.

2. All characters and levels of the game:
"Heroes and Castles 2" offers players a choice of diverse characters, each with unique abilities and customization options. From the durable Knight to the arcane Mage, and the stealthy Assassin, your hero's class determines your playstyle. As for levels, the game features an expansive campaign with numerous battlefields, siege scenarios, and enemy fortresses across a variety of environments. As you progress, you unlock new levels and tougher challenges, culminating in the ultimate test of your leadership and combat skills.

3. What attracts users most to the game:
Players are drawn to "Heroes and Castles 2" for its seamless integration of action-packed combat with strategic elements. The thrill of real-time battle alongside armies under your command, coupled with the depth of RPG leveling and skill customization, offers an engaging gaming experience that keeps players invested. The opportunity to build and upgrade your castle, strategize troop deployments, and directly influence the tide of battle adds to the immersive gameplay.

4. Why it is popular:
The popularity of "Heroes and Castles 2" can be attributed to its successful hybridization of genres, allowing players to enjoy the adrenaline rush of traditional hack-and-slash combat while engaging in the thoughtful planning of an RTS game. The in-depth character progression and the ability to fight alongside armies that obey the player's command create a sense of grandeur and personal stake in the game's world.

5. When the game was released and how many versions are currently available:
"Heroes and Castles 2" was released in May 2015. Since its initial launch, the game has seen several updates and patches that address various aspects of gameplay, balance, and content.

6. The most difficult part of the game:
The difficulty in "Heroes and Castles 2" often spikes with the introduction of tougher enemy waves and siege scenarios. Defending the castle against ever-increasing threats, while also managing your resources and armies, can be quite challenging, with success hinging on strategic foresight and split-second decision-making.

7. Strengths and weaknesses of the game:
Strengths of "Heroes and Castles 2" include its unique genre mix, engaging combat mechanics, captivating visuals, and the depth of strategic elements. As for weaknesses, some players may find the learning curve steep at initial stages, and balancing between character upgrades and castle defenses can sometimes be demanding, potentially overwhelming newcomers to the genre.

8. What other games have been developed by the same developer:
Foursaken Media, the developer behind "Heroes and Castles 2," has produced a number of other games that have captivated audiences. Some of their notable titles include "Block Fortress," "War Tortoise," "Noblemen: 1896," and the original "Heroes and Castles," each showcasing the developer’s penchant for combining various genres to create unique gaming experiences.