How to unlock the last map: Bio Lab

Unlock checklist

• Select Dead Terminal
• Use Default mode
• Finish the run successfully
• Return to arena selection and choose Bio Lab

What makes Bio Lab different

Bio Lab is circular, with toxic fumes around the boundary. Its decontamination process creates a red danger zone, so builds that can keep moving and deal damage without holding one position are easier to pilot.

Boss Rush comes later

Boss Rush is a separate unlock. The official notes say it opens after Hardcore mode for each map, then spawns the Final Boss at the ten-minute mark.

Bio Lab movement plan

Stay near the middle of the current safe area instead of hugging the toxic boundary. When the red decontamination zone starts moving, cross early through the widest lane. Long-range weapons, pets, turrets, and Arrow Rain keep dealing damage while the squad relocates.

Kill lockdown enemies before opening loot

A hacker-type elite can block chests and other interactions through its drone. Follow the lock indicator, remove the controlling enemy, and return after the lane is clear. Standing on a disabled chest while projectile and area attacks stack around it is a common way to lose the run.

A stable Ranger opening

Take one level in Dog and Falcon so both companions begin attacking, then push the crossbow until it has enough shots and penetration to mark a lane. The Barber route marks a wide cone at close range; Shock Spike is safer when the arena is crowded and you need long-range marking.

Huntress and Mechanic cover the weak points

Huntress adds penetration, Arrow Rain, and a moving Zombie Decoy. Mechanic adds Transmitter buffs and a close-range weapon that can cut an escape lane. Level the stronger account character first; an underdeveloped third recruit should provide control before receiving scarce damage upgrades.

Build sustain before the last six minutes

Bio Lab concentrates elites late in the run. Health regeneration, armor, Glass of Milk, or a reliable healing evolution matter more than another small damage roll once normal enemies already die in one pass. Ranger can add healing through Falcon or Incense evolutions, but she has no built-in heal before those choices appear.

Target priority

Remove lockdown drones, laser or projectile elites, and enemies that fill the safe zone with area attacks before collecting optional pickups. Keep bosses moving around the edge of the squad and wait out invulnerable attack phases. A chest is not worth crossing the toxic boundary or standing inside overlapping telegraphs.