Ascend to ZEROBunker Upgrades
Upgrade Type
Permanent
Currency
Zero Keys
NPCs
Multiple
Bunker System Overview
| System | Type | Priority |
|---|---|---|
| Time Machine | Permanent | Highest — compound over runs |
| Zero Keys | Currency | High — avatar stat upgrades |
| NPC Rescue | Unlock | Medium — unlock new functions |
| Equipment Salvaging | Conversion | Lower — convert run loot to permanent |
The Underground Bunker is your permanent progression hub between runs. Rescued NPCs open new functions — upgrades, shops, quests, and equipment management. Invest Zero Keys into avatar permanent upgrades, prioritize Time Machine investments that compound over runs, and convert run loot into permanent assets through equipment salvaging.
Details
Time Machine
Compound upgrades across runs
Effect
Boost starting time and XP gain permanently
Priority
Highest — compounds over every run
Pro Tip
Invest Zero Keys here first for long-term growth
Zero Keys
Avatar stat upgrades
Effect
Permanent avatar stat boosts
Priority
High — invest in your main avatar
Pro Tip
Focus on one avatar before spreading upgrades
NPC Rescue
Unlock new bunker functions
Effect
Opens upgrades, shops, quests, and equipment management
Priority
Medium — rescue during runs to unlock
Pro Tip
Each NPC opens a different bunker function
Equipment Salvaging
Convert run loot to permanent assets
Effect
Converts temporary run loot into permanent upgrades
Priority
Lower — valuable once runs are stable
Pro Tip
Salvage once you consistently reach late stages
Core Mechanics
Bunker upgrades are permanent — they persist across all runs. The Time Machine provides compound upgrades that boost starting time and XP gain. Zero Keys are the currency for avatar-specific permanent stat boosts. NPC rescue unlocks new bunker functions. Equipment salvaging converts temporary run loot into permanent stat bonuses.
Advantages
The bunker provides permanent progression between runs. Time Machine upgrades compound over runs, Zero Keys invest in avatar stat boosts, rescued NPCs unlock new functions. Equipment salvaging converts run loot into permanent assets.
Challenges
Upgrades require Zero Keys which accumulate slowly. NPC rescue requires reaching specific points during runs. Salvaging only becomes valuable with stable runs. Higher-level upgrades have diminishing returns.
FAQ
What should I upgrade first in the Bunker?+
Rescue NPCs during runs to unlock new bunker functions first. Then invest Zero Keys in Time Machine upgrades that boost starting time and XP gain. These compound over runs.
How do I get Zero Keys?+
Zero Keys are earned by completing runs and achieving milestones. The longer your runs and the more bosses you defeat, the more Zero Keys you accumulate.
Is equipment salvaging worth it?+
Equipment salvaging becomes valuable once you have stable runs generating quality loot. It converts temporary run loot into permanent assets. Prioritize NPC rescue and Time Machine first.
Quick Tips
Invest Zero Keys in Time Machine starting time and XP gain first — these compound over runs
Rescue NPCs during runs to unlock new bunker functions and upgrade options
Equipment salvaging becomes valuable once you have stable runs generating good loot
Avatar permanent stat upgrades at the Time Machine are the best long-term investment
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