Casualties: Unknown is a survival game about descending into the cave system of an alien planet to recover lost cargo. The player is one of many test subjects sent into an environment where survival is unlikely. Progress means travelling deeper through the planet while dealing with injuries, limited resources, hostile creatures, and environmental dangers. The journey is divided into 11 layers, and each layer introduces its own conditions and threats. There is also a mystery surrounding what lies at the end of the descent and what happens if the mission is completed.

Descending Through the Planet

Exploration requires caution because falls, enemies, traps, and other hazards can quickly create serious problems. The player searches previous expedition sites and other areas for supplies, tools, medical materials, and useful objects. Around 300 different items can be found during runs. Some discoveries make survival easier, but carrying or using the wrong item can also create additional risks. Crafting allows collected materials to be turned into tools and supplies needed for travelling farther underground.

Injuries and Survival

Health is managed through simulated limb and cardiovascular systems rather than a simple health bar. Wounds can bleed, become infected, and eventually cause the character to lose consciousness. Players need to bandage injuries, control blood loss, and find resources that can be used for treatment. Mood also affects survival, while character traits such as Intelligence, Strength, and Resilience can improve during a run and influence how the character handles different situations.

The main activities include:

•         descending through cave layers and searching for safe routes;
•         collecting tools, materials, medical supplies, and other items;
•         crafting equipment needed for exploration;
•         treating bleeding, infections, and damaged limbs;
•         managing resources while deciding what to carry;
•         avoiding or surviving hostile creatures and environmental hazards;
•         improving Intelligence, Strength, and Resilience during the run.

Careful preparation becomes more important as the descent continues. A small injury can develop into a larger problem if it is ignored, and losing important supplies may make later areas much harder to survive. Players therefore need to decide when to explore for additional resources and when it is safer to continue downward. Loot and danger values can also be adjusted, changing how frequently useful items appear and how dangerous a run becomes.

Runs and Long-Term Progress

Casualties: Unknown is structured around repeated survival attempts rather than traditional missions with checkpoints after every objective. Death can end the current run, so learning how hazards, medical systems, crafting, and resource management work is part of progression. Three characters provide different play styles, giving later attempts another way to change the approach to exploration. Reaching deeper layers requires balancing movement, preparation, health, and supplies while continuing toward the lost cargo and the final part of the planet.