Economy
Understanding credits, income sources, and spending strategies.
Starting Resources
| Resource |
Base Value |
Modified By |
| Credits |
1,500 |
Prestige (+10% per level) |
| Lives |
20 |
Prestige (+1 per 5 levels), Core Reinforcement upgrade |
Income Sources
1. Kill Rewards
Every enemy killed gives credits based on type and wave.
| Enemy |
Base Reward |
Wave 50 Reward |
Wave 100 Reward |
| Scout |
1 |
2 |
5 |
| Armored |
2 |
4 |
10 |
| Swarm |
1 |
2 |
5 |
| Shielded |
4 |
8 |
20 |
| Heavy |
8 |
16 |
40 |
| Stealth |
4 |
8 |
20 |
| Carrier |
6 |
12 |
30 |
| Boss |
50 |
100 |
250 |
| Titan |
100 |
200 |
500 |
Scaling Formula:
- Waves 1-49:
baseReward x (1 + wave x 0.02)
- Waves 50+:
baseReward x (2 + (wave - 50) x 0.08)
2. Wave Completion Bonus
At the end of each wave, you receive:
Base Bonus: 50 + (wave x 25) credits
| Wave |
Completion Bonus |
| 1 |
75 |
| 10 |
300 |
| 25 |
675 |
| 50 |
1,300 |
| 100 |
2,550 |
3. Milestone Bonuses
Reaching certain waves gives extra credit bonuses:
| Wave |
Bonus Credits |
| 5 |
+100 |
| 10 |
+250 |
| 15 |
+400 |
| 20 |
+600 |
| 25 |
+1,000 |
| 50 |
+2,500 |
| 75 |
+5,000 |
| 100 |
+10,000 |
4. Interest
At the end of each wave, you earn 5% interest on your current credits.
Base Interest Cap: 500 credits per wave
Increasing the Cap:
- Investment Returns upgrade: +15% cap per level (10 levels max)
- Large Cap powerup: 2x cap for one game
- Prestige 30 (Veteran): +25% cap
Example:
- 10,000 credits with base cap = 500 interest
- With max Investment Returns (+150%): cap becomes 1,250
- With Prestige 30 (+25%): cap becomes 1,562
5. Wave Bonus Upgrade
The Wave Bonus permanent upgrade adds flat credits per wave:
| Level |
Bonus Per Wave |
| 1 |
+5 |
| 2 |
+10 |
| 3 |
+15 |
| … |
… |
| 10 |
+50 |
Spending
Turret Costs
See Turrets for all costs. Range from $150 (Pulse) to $25,000 (MOAT).
Turret Efficiency Upgrade
Reduces turret costs by 5% per level (5 levels max = 25% discount).
| Level |
Discount |
| 1 |
-5% |
| 2 |
-10% |
| 3 |
-15% |
| 4 |
-20% |
| 5 |
-25% |
Selling Turrets
You can sell placed turrets for a percentage of your total investment.
Base Sell Value: 75% of total spent (purchase + all upgrades)
Increasing Sell Value:
- Salvage Master upgrade: +4% per level (10 levels = +40%)
- Prestige bonus: +1% per prestige level
Example:
- Level 6 Pulse Cannon total cost: 150 + 180 + 270 + 600 + 1,200 + 2,400 = 4,800
- Base sell: 4,800 x 0.75 = 3,600
- With max Salvage Master (+40%): 4,800 x 1.15 = 5,520 (capped at 100% + bonuses)
Economy Strategies
Early Game (Waves 1-20)
- Start with 2-3 Pulse Cannons - don’t overspend
- Save some credits - interest starts building
- Upgrade to level 2-3 - better than more turrets
- Hit milestone waves for bonus income
Mid Game (Waves 21-50)
- Push turrets to level 4+ - major power spikes
- Let interest build between waves
- Balance saving and spending - don’t hoard excessively
- Invest in Investment Returns upgrade early
Late Game (Waves 51+)
- Max out key turrets (level 6) - huge stat boosts
- Interest cap matters more - upgrade it
- Sell and rebuild when strategies need adjustment
- Use credit powerups strategically
Economic Math
Interest vs Spending
Question: Should I save for interest or spend now?
Answer: Generally spend if:
- You’re near interest cap already
- You’re struggling to survive
- The upgrade gives a major power spike (level 4+)
Save if:
- You’re comfortably surviving
- You’re nowhere near interest cap
- Next upgrade is incremental
Sell/Rebuy Efficiency
With base 75% sell return:
- Rebuilding costs 25% of investment
- Only worth it for major strategy changes
- Better with Salvage Master upgrade
With max Salvage Master (115% return):
- Actually profitable to sell!
- Enables flexible repositioning
Quick Reference
| Stat |
Base Value |
| Starting Credits |
1,500 |
| Starting Lives |
20 |
| Interest Rate |
5% |
| Interest Cap |
500 |
| Sell Return |
75% |
| Wave Bonus Base |
50 + wave x 25 |