Nanostray Codes -

Unlocking challenges:

Complete Mitsurin Jungle to unlock Challenges 1, 2. 
Complete Mokuzu Depths to unlock Challenges 3, 4, 5. 
Complete Sunahara Desert to unlock Challenges 6, 7. 
Complete Hibashira Plains to unlock Challenges- 8, 9, 10. 
Complete Sekihi Belt to unlock Challenges 11, 12, 13. 
Complete Sekai Outpost to unlock Challenges- 14, 15, 16. 
Complete Chuuroh City to unlock Challenges- 17, 18, 19. 
Complete Zenshoh Station to unlock Challenges 20, 21 ,22. 

Challenge mode bonuses:

Chuuroh City concept art: Complete Challenge 18. 
Chuuroh City music: Complete Challenge 17. 
Enemy "Masked Raider" model: Complete Challenge 19. 
Enemy "Mr. Slater" model: Complete Challenge 10. 
Enemy "Squidman" model: Complete Challenge 13. 
Enemy "Triple Zero" model: Complete Challenge 5. 
Enemy "Whale-Bot 3000" model: Complete Challenge 16. 
Hibashira Plains concept art: Complete Challenge 9. 
Hibashira Plains music: Complete Challenge 8. 
Mitsurin Jungle concept art: Complete Challenge 2. 
Mitsurin Jungle music: Complete Challenge 1. 
Mokuzu Depths concept art: Complete Challenge 4. 
Mokuzu Depths music: Complete Challenge 3. 
Sekai Outpost concept art: Complete Challenge 15. 
Sekai Outpost music: Complete Challenge 14. 
Sekihi Belt concept art: Complete Challenge 12. 
Sekihi Belt music: Complete Challenge 11. 
Sunahara Desert concept art: Complete Challenge 7. 
Sunahara Desert music: Complete Challenge 6. 
Zenshoh Station concept art: Complete Challenge 21. 
Zenshoh Station music: Complete Challenge 20. 

Unlocking Arcade levels:
In order to unlock the levels for Arcade mode you must complete each level in Adventure mode, under any difficulty setting. In arcade mode the difficulty is set at Expert mode. You will only get three ships and cannot change the difficulty.