Pre-Abyss checklist
Reach Fully Trained by purchasing every Skill Tree node, then bring either Dragon or Ancient Bucket into the Abyss.
Descent tips
Avoid Shark Bait trigger zones. Drain methodically and use the F-key teleport to minimize downtime.
The phone ending
Interact with the lost phone asset at the base of the Abyss to trigger the Find My Phone badge and complete the game.