Here is the full list of all 35 The Alliance Alive HD Remastered achievements.
View the sub ending with Grossa's defeat
View the normal ending
Obtain all maps
Open all portals
Scout 100 recruits
Seal all the Water Devil Dens
Gather 50 Order Gems
Assemble all 12 characters
Unlock Music mode
Gather 100 Chaosium Gems
Give the password to the Black Market
Defeat 500 enemies in battle
Scout 50 recruits
Build your first Guild Tower
Make the Ark able to fly
Rescue everyone at Hakurei Castle
Obtain the Ark and gain the ability to travel freely
Assemble 9 main characters
Defeat a big symbol monster for the first time
Defeat 100 enemies in battle
Acquire all achievements
Defeat all big symbol monsters
View the sub ending where you lose to Kuwalsa
View every ending
Obtain 500,000 So
Acquire 100,000 talent pts
Scout all recruits
Reach top rank with any of the guilds
Learn all Sigils
Learn all Sorcery spells
Learn all Battle Arts
Defeated Kuwalsa within 20 hours
Defeated Kuwalsa within 15 hours
Defeated Kuwalsa within 10 hours
Defeat 1000 enemies in battle