Phosphor

Phosphor is a retro cyberpunk roguelike platformer in which you fight your way down through an infested industrial facility. You play as a reclaimed husk sent into the Underfab, a dead industrial deep lit by the phosphor glow of failing machines. Each descent takes you further through new worlds and biomes as you scavenge weapons, fight hordes and giant bosses, and build a setup that can carry you onward. You can arm yourself from a pool of over 450 weapons and upgrades. When you die, you keep the cores you banked, unlock new operatives and descend again.

Explore the Underfab

The facility is still dying, and its lights can signal either loot or danger. Runs take you through changing worlds, where you gather equipment and learn what each area holds. Loot has six rarities, and weapons have individual effects: shots can pierce, chain, ricochet, charge, steal health, execute weakened enemies or hunt targets on their own.

Weapons and upgrades can combine in several ways:

• Elemental reactions: Fire, toxin, shock and ice can react when you apply a second element to a target already carrying one. Reactions include Thermal Shatter, Superconduct, Combustion and Corrosion.
• Synergy sets: Completing a set changes how you play. Your attacks might ignite, critical hits might execute weakened enemies, or kills might refresh your dash.
• Keystones: These legendary finds alter the rules for the rest of a run, making every shot chain, bounce or trigger an elemental effect.
• Operatives: Unlockable characters have different play styles and kits, including a glass cannon, an armored brawler, a cyberspell caster and a revenant that heals by hurting things.

Play with others

Online co-op supports two players in a full campaign. Both players share a seed-identical world, vote on the path and can trade guns found on the floor. You can revive a partner from a bleedout or spectate until a boss kill brings them back. Twelve co-op-only support weapons give the second player a distinct role.

For competitive play, the versus terminal offers five modes:

• LAST LIGHT: A one-hit instagib match in a shrinking arena.
• ARSENAL: A 12-gun ladder where the gun determines the score.
• DUEL: A mirrored best-of-five match in a purpose-built symmetric arena.
• CROWN HOLD: A mode where position matters more than aim.
• THE GAUNTLET: Both players race through identical mirrored roguelike runs, sabotaging each other's worlds. The build you finish with carries into a final showdown behind the gates. Dying to the machines means losing; arriving first starts a pressure clock for your opponent.

Public matchmaking runs through Steam using a raise-a-flag system, with no queue or waiting room. Matchmade fights count toward a ranked Elo ladder.

Return to the Foundry

After each run, you return to the Foundry, the facility hub where you spend banked cores. You can permanently unlock gear, tune your starting loadout, progress through the forge perk tree, work through Contracts and read the Archive as more of the story emerges.

You can choose from four ways to descend:

• Descent: Start a fresh run.
• Custom run: Add hazards for bigger payouts.
• Daily & weekly challenges: Play the same seed as everyone else and try to beat your own best result.
• ENDLESS: Clear the Core to continue through looping descents for as long as you can keep up.