1. **Introduction of the Game**
Mobile Strike is a thrilling, modern war-themed MMO strategy game that puts you in the role of a commander, requiring strategic planning, alliance teamwork, and tactical prowess to achieve dominance over the battlefield. The game offers a mix of base building, troop management, and real-time combat against enemies from around the world.

2. **All Characters and Levels of the Game**
Mobile Strike doesn't revolve around individual characters like some role-playing games; instead, the focus is on the players themselves as commanders. The levels in the game are manifest through the base's Command Center level, which the player upgrades to unlock new buildings, units, and various other resources and capabilities. There are multiple tiers of troops and defenses to be unlocked, covering ground, air, and technical units.

3. **What Attracts Users Most to the Game**
Users are most attracted to Mobile Strike for its deep strategic gameplay, the excitement of building and defending a base, the social element of forming alliances, and the status that comes with climbing the leaderboard ranks. Additionally, celebrity endorsements, such as those from Arnold Schwarzenegger at launch, also drew considerable attention.

4. **Why It Is Popular**
Mobile Strike has gained popularity because of its engaging content updates, its competitive gameplay, and the massive multiplayer community it fosters. The strategic depth required to succeed, coupled with the social networking aspect of joining forces with other players in alliances, offers a compelling blend of strategy and social interaction.

5. **The Most Difficult Part of the Game**
The most challenging aspect of Mobile Strike can be the late-game content, where strategic planning against equally matched or stronger opponents becomes paramount. Balancing resource management, alliance coordination, and the timing of attacks and defenses often requires careful attention and can be quite demanding for those striving to be among the top players.

6. **Strengths and Weaknesses of the Game**
Strengths of the game include its engaging strategic gameplay, expansive multiplayer component, and the continuous updates that keep the content fresh. However, one of the weaknesses often cited by the gaming community is the heavy emphasis on in-app purchases, which can create a pay-to-win dynamic for those lacking the patience for a slower, more strategic build-up.

7. **What Other Games Have Been Developed by the Same Developer**
Mobile Strike was developed by Machine Zone, Inc. (MZ), the same developer behind the successful Game of War: Fire Age. MZ specializes in highly social and interactive online games that leverage their robust gaming platform to support millions of players simultaneously. Other titles from MZ include Final Fantasy XV: A New Empire, an MMO strategy game that incorporates characters and elements from the Final Fantasy universe.