Complex sentence: Insane Death Mode is only available after a player clears the game in Unmatched Mode, this mode plays in the same fashion as Unmatched Mode but limits player's HP to 1 and will never grow when leveled up.
Split into simpler sentences: Insane Death Mode is only available after a player clears the game in Unmatched Mode. This mode plays in the same fashion as Unmatched Mode but limits the player's HP to 1 and will never grow when leveled up.