Last Fortress: Underground is a strategy defense game developed by IM30. Players will be placed in a post-human era underground castle, facing threats and challenges from the external environment. In Last Fortress: Underground, the player's main task is to build and manage the underground castle to ensure its survival and prosperity in the face of external threats. Players need to build various infrastructures and fortifications, such as power supply facilities, water management, and food reserves, as well as guard against various attacks and invasions from the outside.

One of the core gameplay aspects of the game is defense strategy and tactical layout. Players need to design and arrange fortifications and armed facilities according to the terrain and resource distribution of the castle. Different types of external threats may include monster attacks, resource contenders, or intruders from other underground castles, and players need to respond flexibly to protect their castles and resources through reasonable defense layouts.

In the game, players need to effectively manage and utilize various resources, including food, water and energy. Players can establish farmland and pasture to produce food, and build water source and power plant to maintain the normal operation of the castle. The reasonable distribution and utilization of resources will directly affect the survivability and development speed of the castle. In addition to defending the castle, Last Fortress: Underground encourages players to explore and discover. Players can send scouting teams to explore unknown areas and resource points around the Underground Castle to discover new resources and dangers. Exploration brings new challenges and opportunities, and is a key way for players to acquire rare resources and expand the castle's territory.

The game features a technology development system where players can invest resources and time to develop new technologies and equipment. The advancement of technology will improve the castle's defense capability and resource utilization efficiency, enabling players to occupy a more advantageous position in the fiercely competitive underground world. Last Fortress: Underground supports social interaction and cooperation between players. Players can join or create alliances to share resources, strategies and information with other players to fight against external threats. Alliance members can collaborate on defense and offense, and work together to explore more secrets and challenges in the game world.

Last Fortress: Underground offers players a challenging and surprising underground castle building and defending experience through its deep strategic defense gameplay, rich resource management system, and emphasis on exploration and discovery. Each player can play freely in the game to design and manage their own castle, protect it from external threats through rational strategic layout and technological development, and seek to grow and prosper in the competitive underground world. With the continuous update and development of the game, players are expected to discover more secrets hidden in the underground world and become the strongest in the field of underground castles.