A few more NNK2 tips below. Nothing missable or glitching, just to make life a little easier:
- Don't complete the kill 50 tainted monsters (out of 50) until you completed collecting 30 Songbooks (out of 31) and 30 Higgledy Stones (out of 30). Reason is that after killing the 50, it will actually spawn another 10 that are much higher level (70+ to 90), and these can block your way stopping you from reaching some songbooks and higgledy stones. (I am level 99 and a couple of them kicked my ass. They are tougher than the final dungeon boss needed for trophy.) These 10 extra are optional, no trophy for them.
- The game doesn't track the songbooks for you. Either you manually track them or, in kingdom builder, don't talk to the guy at the symphonium. When you collect a songbook, it's listed in Items>key items. But once you talk to him, you will hand over all the books and wont be able to tell what you have or not. Of cos you can look up collectible guides but if you don't know what you are missing, you have to waste time checking every spot listed (and many are very vague, like it's in a chest in this region, when there are some 20 chests around).
- There are skirmishes in the story missions and side missions (complete them all). Then there are more skirmishes that randomly spawn (and respawn) all over the map. You can't easily tell which random skirmish you have done, have to accept the mission, see whether hard mode is unlocked (if so, means you already done it before). Try to track them manually. There's a trophy for completing 50 unique skirmishes (story, side quests, random). Basically you need to complete every one of those randoms (I counted around 33, a few may be overlaps with side quest ones). I have a check list
here.