Skulls

Skulls are optional difficulty modifiers which can be activated in Defiant Mode, or the Daily and Weekly Hardcore Challenges. They normally make the game more difficult for the player.

Skull Name	Ingame Description	Effects
Marathon	All levels are longer. Prepare for the longest journey.	Causes all levels to be as long as level 8. (???)
Famine	No health items drop. Ration well.	No health Pickups drop- not from enemies, not from crates, not from boss crates or speed-reward crates. Health Dispensers do not spawn. <Are they replaced with Crimson Dispensers? Seeing more of those...> Vitality Scavenger does not drop. <And if you have it from a prerun Soul Shop purchase, it won't work?> Seven Leaf Clover will, but it won't drop health. Augments that increase maximum HP, such as Life Extender, increase current HP as normal. Augments that heal without spawning health pickups, such as Health Nut, Regenerative Plating, or Owlhawk's Reign, work fine, and are utterly mandatory for survival. <Drop rates for other stuff don't seem affected: crates ordinarily containing health simply contain nothing.>
File:Skull Bankruptcy.png Bankruptcy	No nuts drop. Make your own way.	No nut Pickups drop. <Nut Augments?>. Shops and all Dispensers no longer appear.
Purist	No movement upgrades or Core Augs drop. Paddle your own canoe.	Ninja Sash, Mass Marginaliser, Mass Concentrator and <Crisis Overdrive?> no longer appear. No Core Augs appear. Glory Rooms offer regular Augs as a reward.
Lightning	The game runs at 150% speed. Be swift as a coursing river.	Everything, including the player character's actions, occurs 50% more quickly.
Rock	Spikes, pits, spike-like things, lasers and lava (of any colour) are fatal. Remember your ancestors.	Spikes, pits, burners, thorns, lasers and lava all deal 9,999 damage. Cannot be used simultaneously with Stone (?)
Swarm	More enemies spawn. They will come for you. Your fate is known.	Twice as many enemies spawn.
Toxin	When the bonus timer runs out, you'll be poisoned until you die. No bonus chest.	No bonus chest appears. When toxin timer hits zero, you take 1? damage every 10? seconds. Toxin timer stops upon reaching the boss gate.
Final Destination	No items. Fox only.	No items spawn, ever.
Furor	Enemies act faster. Stacks with lightning. Can you break their technique?	Enemies act at <150%?> speed. Some enemies are not affected.
Wrath	Enemies deal more damage. You've never looked so frail.	Enemies deal double damage.
Undying	Enemies have more health.	Enemies have double health.
Stone	Damage from level hazards is quadrupled. Dream vaguely of your ancestors.	Spikes, pits, burners, thorns, lasers and lava all deal quadruple damage. Cannot be used simultaneously with Rock (?).
Endless	The journey doesn't end until you do. (WARNING: Not well-tested. May crash at high levels.)	At the end of every level starting with level 8, the player can choose to either continue to another standard level or proceed to the Station levels (choosing the latter will allow the player to win the game by reaching the end of the second Station level). Enemy damage and boss health and damage increase gradually beyond level 8. Damage increases based on the Fibonacci Series (at level 9-16 the damage increases to 2, then 3, 5, 8, 13, etc.).
High Tide	Zone generation level +4. Use if "Starting at Level 5" sounds fun. You're going to die a lot.	Level difficulty is taken from four levels down the line, basically starting you at Level 5.
Destiny	Only one next-level portal at each level's end. Your fate is written.	Only the first boss portal works - the other two are always broken.
Dearth	Only the first three bosses grant their normal rewards. Choose wisely.