1. Introduction of the game:
"The Walking Dead: Road to Survival" is a gripping role-playing game for mobile platforms, set in the harrowing world of the iconic comic series created by Robert Kirkman. In this intense game, players must navigate through a post-apocalyptic environment teeming with flesh-hungry walkers and treacherous human enemies. Your choices will determine who survives in this epic struggle for power and redemption.

2. All characters and levels of the game:
Featuring a wide array of characters from "The Walking Dead" comics, players can collect and upgrade iconic characters like Rick, Michonne, and The Governor. Each character belongs to different classes and tiers, each with unique skills and abilities to leverage in battle. The game unfolds over various levels and story missions, challenging players to build their strongholds, manage resources, and lead their group of survivors in tactical turn-based combat.

3. What attracts users most to the game:
The blend of strategic gameplay with a rich narrative tied to "The Walking Dead" universe draws players into "Road to Survival." Fans are particularly attracted to the opportunity to make critical decisions that influence the storyline, creating a personalized adventure. The intense PvP modes, engaging cooperative play with factions, and the thrill of collecting favorite characters are key attractions.

4. Why it is popular:
The game's popularity is largely due to its connection with the acclaimed "The Walking Dead" franchise. The combination of authentic storytelling, compelling character development, strategic resource management, and the social aspect of forming alliances resonates with gamers and fans of the series alike. Additionally, regular updates and events in the game keep the content fresh and the community engaged.

5. When the game was released and how many versions are currently available:
"The Walking Dead: Road to Survival" was initially released in August 2015. As a live-service game, it doesn't have multiple versions in the traditional sense but has been continuously updated and expanded since its launch, providing a constantly evolving gaming experience to its players.

6. The most difficult part of the game:
One of the most challenging aspects of "Road to Survival" is the PvP combat in the high-tier faction wars, where players are pitted against others in strategic battles that require a deep understanding of character abilities and optimal team compositions. Perfecting these skills and strategies while going up against the most competitive players can be a daunting task.

7. Strengths and weaknesses of the game:
The game's strengths lie in its engaging gameplay mechanics, the compelling Walking Dead storyline with meaningful choices, and its extensive character customization. However, the game has been criticized for having a steep learning curve, its pay-to-win elements that can favor players who spend money, and instances of imbalanced gameplay that can lead to frustrating experiences for free-to-play users.

8. What other games have been developed by the same developer:
"The Walking Dead: Road to Survival" is developed by Scopely, a mobile gaming company known for creating and publishing a range of successful games. Other notable titles from Scopely include "Star Trek Fleet Command," "WWE Champions," "YAHTZEE With Buddies," and "Marvel Strike Force" among others, which offer similar levels of strategic depth and fan-engaging content across different popular franchises.