After completing Standard New Game, you unlock New Game+. Unlike other games, New Game+ is not a continuation of New Game. As such, it is advisable to save in a new save file if you have not fully collected/unlocked everything in New Game. Here is the list of changes in New Game+

Default cloak is now black colored.
Max Health is capped at two.
The ocher outfit cannot be used.
Cloak cannot be changed.
Sword and bot can be changed, along with their added effects.
All sword and dash skills are unlocked.
All other upgrades (health pack capacity, weapons, weapon ammo capacity, grenade) and collectibles (monoliths and gearbits) have been reset.