**1. Introduction of the Game:**
Girls X Battle is an engrossing mobile role-playing game (RPG) that seamlessly blends elements of strategy and anime-styled visual appeal. Players assume the role of a commander, whose task is to recruit and manage a squad of female warriors, known as "Battle Girls," each with unique abilities and backstories. Through a combination of tactical combat and resource management, players must lead their Battle Girls to victory against various challenges.

**2. All Characters and Levels of the Game:**
Girls X Battle boasts an expansive roster of characters, each with their distinct skills, stats, and classes. From front-line tanks to damage dealers and support units, the Battle Girls come in various levels that unlock new capabilities and powers as players progress. As commanders, players strategize on the best formations and team synergies to conquer the multitude of levels and arduous boss fights presented in a variety of thematic stages and events.

**3. What Attracts Users Most to the Game:**
The game's immersive quality is a significant draw for users, coupling an alluring anime aesthetic with intricate character development that offers depth beyond the surface battle mechanics. Additionally, the strategic layer of the game, enhanced by the vast array of character combinations and the excitement of unlocking new Battle Girls, keeps players engaged and continually experimenting with various team setups.

**4. Why It Is Popular:**
Girls X Battle has gained popularity due to its rich blend of engaging gameplay, captivating character designs, and satisfying progression system. The game caters to both casual and hardcore gamers with its varying levels of depth and complexity, allowing for a broad audience reach. Its frequent updates and events also help maintain a dynamic and ever-evolving gaming experience.

**5. The Most Difficult Part of the Game:**
For many players, the most challenging aspect of Girls X Battle can be the late-game content where strategic planning, optimal team composition, and character synergy become crucial. Perfecting formations to counter tough boss mechanics and competing against other players in the PvP arena often prove difficult and require a deep understanding of the game's nuanced systems.

**6. Strengths and Weaknesses of the Game:**
Strengths of Girls X Battle include its extensive character collection, appealing art style, and strategic depth. However, weaknesses may be seen in its potential for a grind-heavy progression system and the reliance on in-app purchases for faster advancement, which can be off-putting for some players who prefer not to spend money.

**7. What Other Games Have Been Developed by the Same Developer:**
The developer behind Girls X Battle, Carolgames, is known for other similar titles that often incorporate anime themes and strategic gameplay elements. Games such as "Girls X Battle 2" and "Ninja Girls" are also part of their portfolio, providing similar experiences with unique twists to retain the interest of the player community.