You will only get 100% if you do it in one playthrough. Extras menu can get you some trophies, I think, but not 100%.
And, honestly, 80% sounds like you missed an end somehow. I think 60% is what you get for completing one of the ends... so that would indicate that each end has a weight of 20%.
CelticRedemption wrote:No you don't. I actually tested that last ngiht =D all the trophies that are marked as "need 3 hearts" can actually be gotten with 2 hearts and accepting their confessiong to get a big heart.
...Except Good Mood With Finnel 2 (and the related Saki trophy) because it comes in Phase 3.
Hrmm.. I see I made an error in my post, I meant talk topics, not trophies. My bad.
Also, what I also tested was getting the 100% cosmosphere trophy in separate playthroughs, which also ended up working. So actually I'm positive about that being the case.
And about those "good mood with XX 2" trophies... If you keep a save at MYU and just beat it and keep playing for like 15-20 minutes, you get that scene and its trophy... So you can reload to the MYU fight and set up for true end second reyvateil, normal/true Tyria and Cocona. ( assuming you've done a pure playthrough of 1 reyvateil so you're level 99 and can breeze through the story the second time ).
The last possible part to finish someone's cosmosphere and get locked into their ending is the moment before you make that part for the satellite.