HorrorVale Heights is divided into three main areas: the base of the mountain, Hodgepodge Hideaway, and the ridge past Hodgepodge.
HorrorVale Heights Base
After deactivating the five generators, the player reaches the base of HorrorVale Heights. This is where the player can find Antoinette's house. The primary aim of the mountain's base is to traverse the caves to deactivate a number of electric gates to progress up the mountain. Enemies that can be encountered here include: Malfunctioning Vampire, Skullking Crab, Perplexing Pumpkin, Deranged Munster, Perturbed Snakehen, Don't Know What, and Puppet Boyo.
A small community of rejected Frankenling Experiments. Hodgepodge Hideaway is the midpoint of climbing the mountain and requires the player to traverse the neighboring cave system to acquire Sparkshrooms. Upon being completed, the player is then able to advance to the upper portion of the mountain. This settlement is also where Jiang can be encountered for the second time, having expanded her inventory of wares for the player to purchase equipment and items. Enemies that can be encountered here include: Terrible Fate, Severed Hand, Horror Chimera, and Ghostshroom.
The final part of the mountain before reaching the Lab. Enemies that can be encountered here include: Maniacal Balloon, and Lightning Spirit. After reaching close to the summit, the player will be ambushed by large arms sprouting from the ground which will chase the player. After reaching a dead end, the player will then encounter the miniboss Grave Hands. After his defeat, the player is able to progress to the Lab.