Swarm Below is an action indie casual game for PC that places players in an underwater roguelite survival experience. You control one of several divers who descend into a reef filled with aggressive marine life, relying on automatic weapons while focusing on movement and resource collection to survive escalating threats.
Gameplay
The core loop centers on short runs where limited air and constant hunger from surrounding fish force constant motion. Your equipped weapon fires independently, freeing attention for dodging, collecting pearls, and selecting upgrades upon leveling. Early stages feature manageable numbers of enemies that quickly multiply until the environment feels overcrowded. Permanent progression comes from pearls spent on lasting improvements between runs, alongside quests that reward ongoing play and a codex that tracks discoveries.
Each run builds toward powerful combinations through 28 weapons and supporting passives. Nineteen weapons evolve into stronger forms when paired correctly, while relics and charms add further layers. A single strong chest can shift a struggling attempt into widespread destruction. Controller support makes precise maneuvering comfortable, and the game runs well on Steam Deck for portable sessions.
Game Modes
Runs unfold across distinct reef layers that increase in difficulty. The Shallows give way to the Twilight and finally the Abyss, each introducing new enemy types and environmental pressures. After defeating a stage boss, a whirlpool appears that lets you carry your full build forward or linger for higher-value pearls before shades arrive. Five Pressure settings adjust overall challenge, with the highest called Crush Depth pushing endurance and build optimization to extremes.
Divers and Builds
Eleven distinct divers alter how runs feel. Gale emphasizes high damage at the cost of durability. Barnacle absorbs hits effectively but lacks natural recovery. Tide sustains itself through eliminations. Bosun handles multiple weapons simultaneously. These differences encourage experimenting with loadouts across repeated attempts. Weapons range from harpoons and depth mines to rivet guns, jellyfish drones, and homing torpedoes that scale into coordinated packs. Stacking elements creates explosive screen-clearing effects once synergies activate.
Enemies and Bosses
Nine bosses guard the depths, including The Lantern, The Moray, The Bloat, and The Smasher, with Mother waiting at the lowest level accompanied by additional threats. Regular encounters feature reef sharks, sea lions, spider crabs, and occasional golden fish worth pursuing for extra rewards. Enemy density rises steadily, turning early caution into frantic positioning as numbers overwhelm open space.
Is It Worth Playing?
Swarm Below suits players who enjoy movement-focused action with roguelite progression and build crafting in a compact package. Every run contributes to long-term growth through pearls and unlocks, reducing frustration from early failures. The variety across divers and weapon evolutions supports repeated dives without feeling repetitive, while Pressure levels extend challenge for those seeking tougher tests. Casual accessibility pairs with depth in systems that reward observation and adaptation over precise aiming. Those drawn to underwater themes and automatic combat loops will find consistent value in its loop of short sessions building toward stronger permanent options.