The UnderGrowth

Grow your underground empire! Cultivate rare species, harvest spores, and tap your way to fungal dominance. Permanent boosts now available in the Shop!

Deep beneath the surface, a living network stirs. You are the cultivator — tap to grow, produce to expand, and unlock the hidden species of the underground. The UnderGrowth is an idle clicker built around the slow, satisfying rhythm of fungal growth. Tap to generate mycelium, watch your production tick upward, and make strategic choices about when to prestige and how to spend your hard-earned spores. GROW YOUR NETWORK Tap the screen to produce mycelium and build your underground operation. Upgrade your production rate and watch your numbers climb — even while you're away. UNLOCK RARE SPECIES Discover and collect a variety of unique underground species, each with its own look and lore. Watch your ecosystem come to life as your collection grows. PRESTIGE & EVOLVE When the time is right, reset your progress and carry forward bonus spores that make each run more powerful than the last. Every prestige brings new potential. BOOST YOUR OPERATION Earn temporary boosts through rewarded ads — double your production for an hour, multiply your tap power, or claim an instant burst of progress. For players who want a permanent edge, the Shop offers one-time upgrades that stay with you forever. BUILT FOR IDLE PLAY Your mycelium keeps growing whether you're actively tapping or not. Check back, collect your haul, and keep expanding. No energy timers. No pay-to-win walls. Just the quiet satisfaction of watching something grow.