Dig towards the center of the Earth: 15 layers, from grass to the ABYSS (23.5MM).
WASD / Arrows: move and mine (hold)
E or button: upgrade pickaxe (×1.3 damage per level)
Each block gives small coins. Find minerals and the rare Exponent Artifact (0.1%) that multiplies your power ×2 to ×20. Sell items to earn real money.