Put them in the Support section in Extras.

Code	Effect
amaranth	Catacombs available on all characters, up to Spellsword unlocked.
batstab	All rogue upgrades.
bigadventure	All adventurer upgrades.
dabigunlock	All characters to Cultist, Endless and Diamond unlocked.
demonbind	All cultist upgrades.
humphrey	Tower available on all characters, Adventurer unlocked.
nicescrolls	All spellsword upgrades.
stubble	All warrior upgrades.
thorns	Catacombs available on all characters, up to Cultist unlocked.
wizardtalent	All mage upgrades.