You can increase Dead Cells game difficulty and face much tougher enemy by using the Boss Steam Cells. You can find a glass tube below after you see all the weapons and skills you unlocked. In this you will see the Stem Cells, you have to inject to increase the game difficulty. There are total 5 Boss Steam Cells you can inject in the tube to face the toughest enemies.

Boss Steam Cells & Their Difficulty Level

You can see the list of all five Steam Cells and how they impact the game difficulty level. Plus you also get some bonus for defeating stronger enemies.

Boss Steam Cell – 0

  • Difficulty Level – Normal.
  • Foundry Level – +
  • Health Fountains – Lower number of health fountains but full refill after every biome.
  • Dead Cells Drop – Regular.
  • Item Levels in Biome – Regular.
  • Enemies – Regular.
  • Collect Next Boss Steam Cell.
  • Infection – None.

Boss Steam Cell – 1

  • Difficulty Level – Hard.
  • Foundry Level – ++
  • Health Fountains – Lower number of health fountains, you get a mini recharge drops after you deal with the first boss. You can use it one time to refill health flask.
  • Dead Cells Drop – 2x Cell drops.
  • Item Levels in Biome – Regular.
  • Enemies – One new enemy in each biome.
  • Collect Next Boss Steam Cell.
  • Infection – None.

Boss Steam Cell – 2

  • Difficulty Level – Very Hard.
  • Foundry Level – ++
  • Health Fountains – No Health Fountains, instead you can buy single flask recharges from Food shops.
  • Dead Cells Drop – 2x Cell drops.
  • Item Levels in Biome – Regular.
  • Enemies – Similar to 1st Boss Stem Cell.
  • Collect Next Boss Steam Cell.
  • Get access to Insufferable Crypt through the door in Ramparts.
  • Infection – None.

Boss Steam Cell – 3

  • Difficulty Level – Expert.
  • No Health Fountains, instead you can buy flask recharges from Food shops.
  • Foundry Level – S
  • 3x Cell drops.
  • Taking hits will cause infection.
  • Enemies – Similar to 1st Boss Stem Cell.
  • Item Levels in Biome – +2.
  • Infection – None.

Boss Steam Cell – 4

  • Difficulty Level – Nightmare
  • No Health Fountains, instead you can buy flask recharges from Food shops.
  • Foundry Level – S
  • 3x Cell drops.
  • Item Levels in Biome – +4.
  • Enemies – One new enemy in each biome.
  • Infection – Taking hits from some enemy will cause infection. It also includes some foods.

So these are all the stats of modifiers you will see once you use each Boss Stem Cells to increase the game difficulty level.