We (finally!) got the re-release ready! In short, it includes a bunch of fixes on bugs, balancing and smoothness and adds the online achievements, but here you have the changelog anyway:

Character Changes
Alma
+Removed the Kit swapping mechanic, Alma can use any skill now without needing to swap kits.
+Added a new mod that adds DEF Down to enemies when analysing.
Isaac
+Added a new personal mod that gives Isaac a 50% chance to create a duplicate item for the party to use when Mixing in battle.
Ellis
+Added a new battle mechanic, Delayed, Ellis's skills that affect the flow of battles have been made stronger but each battler can only be negatively effected once between each of their turns.
+Ellis now learns his skill in a set order at set intervals.
+Added a new mod that lets Ellis get the first turn.
Ezekiel
+First Strike has been weakened.
+Added a new mod that gives the party 10% HP regen (at least until they die).

The new mods are created by crafting using items you find in the field.

Battle Changes
+Added difficulty option
+Previous difficulty now the Normal Mode difficulty
+Hard mode has been added.
++Most enemies have been made stronger
+Charged Terrors' Thunder Clap now hits 3 times instead of 6.
+Superboss is now immune to Ice and Thunder.
+All damage has been increased by 60%.
+Animation speed for actors has been increased.
+Max Agility is now 200.

Added online achievements
+If you've played any other game with the same script then your account will automatically be found.