This is a fantastic adventure setting that perfectly captures a classic pulp, sword-and-sorcery feel. The backstory of the ape-god Barong, his usurpation of a cosmic entity, and the forging of the Obsidian Artifacts is a strong and evocative premise for any campaign.
The design provides a great sandbox for exploration. The factions are a real highlight; the conflicting goals of the ambitious Goblin King, the secretive Serpent Priestess, and the dutiful Ape Vampire Lord create a dynamic and dangerous political landscape for players to navigate. The random tables are also concise and useful, providing all the necessary tools to run an extended jungle crawl.
The entire document is a great example of a usable and inspiring adventure toolkit.