The mad scientist left in the mansion the results of his last experimentations : Mutations. You can find it in every game you play. They are power ups and abilities you can put on your character. Increase fire rate, becoming insensitive to fire or ice… More than 30 mutations are available! Permanent, you can activate it before every game thanks to the crystals.
This new money is a rare resources that you can loot in chesters or enemies. To use it to pay mutations, you’ll need to find a bank, and store it. Beware, if you get a gameover before banking crystals, you’ll lose them.
You can use them to pay upgrades at the beginning of each level too. It’s up to you to explore every inch of the map and manage your crystals expense!