Direct answer
Progress by catching or hunting fish, selling them, buying equipment and weapons, completing quests, defeating bosses and reaching new islands. The safest route is to upgrade for the next verified obstacle.
Progression priorities
Income
Secure repeatable catches before spending heavily.
Secure repeatable catches before spending heavily.
Utility
Favor tools that unlock or simplify objectives.
Favor tools that unlock or simplify objectives.
Survival
Prepare before boss encounters or unfamiliar islands.
Prepare before boss encounters or unfamiliar islands.
Exploration
Move on once the current area's purpose is complete.
Move on once the current area's purpose is complete.
When to spend money
Buy when a purchase reduces a current bottleneck: catching, transporting, surviving, finishing a quest or confronting a boss. Avoid exact “best upgrade” claims unless they are tied to a tested game version.
Fact check: August 24, 2026 · Primary factual source: official Steam app data (App 4001890).