1. Introduction of the game:
"Star Wars: Galaxy of Heroes" is an enthralling mobile collectible RPG developed by Capital Games and published by Electronic Arts. Launched into a galaxy far, far away, players have the opportunity to assemble their dream team of iconic Star Wars characters and battle in legendary locations. Whether you prefer the strategic squad building or adrenaline-pumping turn-based combat, this game promises a deep, rewarding experience for both casual and hardcore fans of the Star Wars saga.

2. All characters and levels of the game:
The game boasts an extensive roster of characters from various Star Wars eras, including heroes and villains from the original trilogy, the prequels, the sequels, "The Clone Wars,” and "Star Wars Rebels," along with others from the expanded universe. Each character comes with unique abilities and can be leveled up and equipped with gear to enhance their power. As players progress, they unlock new challenges, story missions, and special events that test their managerial and tactical prowess across a multitude of levels and environments.

3. What attracts users most to the game:
Fans are drawn to "Star Wars: Galaxy of Heroes" for its collectible nature, as they embark on a quest to unlock and upgrade their favorite characters. The game capitalizes on the rich lore of the Star Wars universe, combining it with strategic gameplay, squad customization, and large-scale guild events. The chance to create unbeatable teams and participate in epic battles against players from around the world offers an engaging experience that keeps users coming back for more.

4. Why it is popular:
The game's popularity stems from its authentic Star Wars experience, inclusive of impressive visuals and sound effects that resonate with the franchise's fans. Additionally, its strategic depth, regular content updates, and in-game events aligned with Star Wars movie releases contribute to its sustained popularity. Another factor is the sense of community in guilds, where players work together to tackle cooperative challenges.

5. When the game was released and how many versions are currently available:
"Star Wars: Galaxy of Heroes" was first released on November 24, 2015. Since then, it has gone through numerous updates, continuously adding new content and features. While the game itself has not seen distinct "versions" in the traditional sense, it’s maintained through a progression of patches, updates, and expansions that enhance the game over time.

6. The most difficult part of the game:
High-level raids and player versus player (PvP) arenas represent some of the most challenging aspects of the game. These require well-constructed teams, strategic thinking, and sometimes a guild's collective effort to overcome. Events with Legendary and Mythic tiers are also notably tough, demanding a deep understanding of character synergies and game mechanics from the players.

7. Strengths and weaknesses of the game:
Strengths of "Star Wars: Galaxy of Heroes" include its extensive and diverse character collection, the authenticity to the Star Wars universe, and the satisfying strategic gameplay. However, its weaknesses are often highlighted in the form of a steep learning curve for new players, the substantial grind needed to progress at higher levels, and a monetization model that can encourage a "pay-to-win" environment.

8. What other games have been developed by the same developer:
Capital Games is primarily known for their work on "Star Wars: Galaxy of Heroes." However, as a studio under the umbrella of Electronic Arts, they contribute to the expansive portfolio of EA's mobile games and leverage their experience in developing enticing games that appeal to a broad audience. The developers often collaborate with other EA teams to contribute to new titles and projects within the company’s vast gaming ecosystem.