ORDERRecommended Upgrade Order

First weapon upgrade to smooth the early game
Pufferfish Tube for Ancient Sands access and the first serious money jump
Advanced Gun for your first major DPS leap
Anglerfish Tube when deeper routes start paying off
Late-game gun upgrades once the deep route is stable
Wild Tube or equivalent endgame tube path before serious Sunken Wilds or deep-route optimization

Tube upgrades often pay for themselves faster than weapon greed because they unlock better fish first.

ROIROI Analysis

Upgrade	Why It Matters	Expected Effect
Early gun upgrade	Cleaner fish clears	Safer early farming
Pufferfish Tube	Ancient Sands access	Bigger income jump
Advanced Gun	Fast DPS increase	Shorter kill times
Anglerfish Tube	Deeper routes	Higher-value species
Late-game guns	High-HP target efficiency	Better shark and endgame routes

Zone	Best Tube Target	Best Gun Target	Why It Matters
Forgotten Deep	Normal Tube into Fire Tube	Beginner's Gun into Advanced Gun	Low-cost route smoothing while you build your first real cash stack.
Ancient Sands	Pufferfish Tube	Advanced Gun into Wasted Gun	This is the first route where better oxygen and DPS create a major money jump.
Spirit Roots	Oxy Tube or Plane Tube	Magroot Gun	This stage rewards cleaner route control more than greedy under-gearing.
Sunken Wilds / endgame	Wild Tube or Banana Tube	Ruined Gun or Plunger Gun	Current high-end intent is about the cleanest all-round setup, not just one inflated stat.