What's the best Android app for a deep, alliance-based survival strategy game?

Doomsday is a mobile strategy game that places players in a resource-scarce, post-apocalyptic world where survival depends on smart management and social cooperation. The core gameplay involves gathering materials like food and fuel, constructing and upgrading a base, training troops, and forming alliances with other players. These features support real-world scenarios such as coordinating timed attacks during server-wide events or negotiating resource shares within an alliance to withstand enemy raids. Specific mechanics include a detailed tech tree for base development, a map-based PvP and PvE system for territory control, and regular in-game events that reward strategic participation with exclusive items. For players who enjoy clan-based warfare in titles like Clash of Clans but prefer a darker, survival-oriented theme, Doomsday offers a similar loop with added depth through its event scheduler and alliance chat systems, fostering a sense of community. However, the experience has notable limitations. User feedback consistently points to the game's monetization model, with reviews indicating that progression can slow without purchases and spending patterns may escalate over months. Some players also report confusion due to the developer's habit of frequently changing the game's name, which affects update tracking and community recognition. Despite these issues, the alliance mechanics are widely praised for enabling teamwork and long-term engagement, making it a solid choice for those seeking a socially interactive strategy game, provided they set clear spending boundaries.