The Volcano is the nemesis of Perk Benefits! The Volcano meter slowly fills over time - once it reaches the top it erupts, which temporarily makes earned Perks inactive and blocks new progress on current Perks.

You can help cool the Volcano by playing special levels marked with a Tribute (see "What is a Tribute"). Keep earning Tributes to keep the Volcano from filling, so you can keep progressing on Perks!