Successfully complete the game to unlock the Hardcore difficulty.
Extra animation sequence
Get a 100% game completion to view an extra animation sequence.
"Staff Credits" option
Successfully complete the game to unlock the "Staff Credits" option at the "Extras" menu.
Easy Daemon Lord Reborn battle
Although the Daemon Lord Reborn is normally defeated by depleting its
health and triggering a finishing sequence while it is stunned, there
is a glitch that allows the Boss to be stunned at the beginning of the
fight. To do this, wait until the Daemon Lord attacks, and use the
magnetic railing above to get to the opposite side it is facing. Make
sure to give yourself enough distance from the Boss so it will not
counterattack with its tail. Drop down, charge up the bat projectile,
and time its release so that it collides with the Daemon Lord's sides as
it turns around. If done correctly, the Daemon Lord will now be
stunned, and open for a finisher -- which normally is not possible until
several phases of the fight have passed. Although the following
sequence will appear strange due to Alucard and the Daemon Lord clipping
though objects that normally would not be there, the cutscene will
nonetheless conclude with the Boss being defeated, and you being awarded
the Demonic Wings.