- Estimated achievement difficulty: 3/10
- Offline: 10 
- Online: 0
- Approximate amount of time to 1000: 45-70 hours
- Minimum number of playthroughs needed: 14
- Number of missable achievements: None!
- Glitched achievements: None!
- Do cheat codes disable achievements?: No cheats
- Does difficulty affect achievements?: No
N3 is actually an easy 1000 and more or less a fast 800. This game is similar to "Dynasty Warriors" because like in those games, you have to fight against hordes of enemies.
You have to play through the game with each character TWICE! On the 1st playthrough, you will receive the achievements for finishing each character's story. You have to be on level 9 with each character before you can start your 2nd playthrough. Getting to level 9 with each character is the time consuming part.
You will have to finish the story with every character on your first playthrough. You will get the achievements "Clear Inphyy", "Clear Aspharr" and so on...
After you have completed the story with each character, you should unlock Vigk Vagk (Mystery character). Finish his storyline as well. That will give you the "Clear the mystery character" achievement.
After that, you should load up "Inphyy's" save file and you will see that you have unlocked the special mission. First, you should level up Iphyy but if she is already a level 8 or 9, you can give it a try. Check out the achievement guide below for the perfect method. As soon as you defeated the King of Nights you should unlock the "Clear special mission" achievement.
Getting an A or S rank on every mission:
This shouldn't take too long. You will have already achieved a lot of A ranks on your first playthrough. Only a few missions should give you problems. For example, the woods mission with Iphyy. Whenever you are stuck on a mission you can look for advice in the achievement guide below or go to the Niney Nine Nights forums and read what other people did to get A or S ranks there.
Level up all characters to LVL9:
Let's move on to the time consuming achievement. After you finish everything I mentioned above, you should be at least on level 6 or 7 with each character. So now you have to boost them up to level 9. You can read the guide below to see which missions are best to level up on or you can just simply check your stats and repeat the battles where you killed the most enemies over and over. This will take you a lot of time especially with Tyurru or Vigk Vagk.
Once all of your characters have reached level 9, you can start your 2nd playthrough. Make sure you note every mission you completed with the level 9 character. This should be a piece of cake.
Ninety Nine Nights is an easy 1000 but you will spend a lot of time leveling up all the characters to level 9.