Quotes: Harder Than Hard

"You will not survive."
— Description of Veteran difficulty in Call of Duty series, as well Modern Warfare

"This mode is difficult!"
— Announcer in DDRMAX through Dance Dance Revolution SuperNOVA 2, on selecting the Harder Than Hard Challenge mode

MetaSeraphim: I finally beat impossible mode, after 6 days of non-stop trying.
DANGER - Are you prepared to battle sheer despair? (NO) (BRING IT)
Ultra Mode warning screen, Mushihime Sama (English-language iOS ver.)

DANGER - This style is customized for advanced players. Proceed only if you have prepared yourself.
Strong Style warning screen, DonPachi Resurrection Black Label

Deity — Muahahaha! Good luck, sucker!

Good luck.
The loading screen for "Through the Fire and Flames" on Expert difficulty, Guitar Hero III: Legends of Rock

"You face opponents who have never known defeat, who laugh in alien tongues at your efforts to survive. This is suicide."

"Tremble as teeming hordes of invincible alien monsters punish the slightest error with instant death... again and again."
Halo 3, 3: ODST, Reach and 4

Do you hate yourself, or are you supremely self-confident? This difficulty requires a strength of heart that never gives in.