Rockman No Constancy

Rockman No Constancy is a ROM hack of Rockman 2 by Japanese ROM hacker IKA. It features are awesome graphics, great music, and insane difficulty, making it one of the most well-known ROM hacks out there.

Comes in Normal (normal difficulty for Mega Man) and Hard (no Mercy Invincibility; have fun) versions.

Tropes present in this game:

 * Advancing Boss of Doom: The Mecha Dragon chase becomes an insanely fast version of this.
 * An Ice Person: Wood Man.
 * Blackout Basement: One section of Flash Man's stage. Particularly infuriating in that it ends up hiding several blocks.
 * Blow You Away: Air Man.
 * Boss Rush: As per series tradition, though with slippery floor.
 * Bullfight Boss: Heat Man.
 * Chekhov's Gun: Early on in Flash Man's stage, you come across a boss gate that's blocked off. That same gate leads to the final boss much later on.
 * Color Coded for Your Convenience: Mega Man's default color in the Hard version is green (compared to his normal blue).
 * Dummied Out: This song was used in the first build of the game for Wily Stages 3 & 4, and subsequently cut.
 * Eternal Engine: Metal Man's stage and most Wily stages.
 * Floating Continent: Air Man's stage seems to be this.
 * Gusty Glade: Air Man's stage.
 * Harpoon Arm Cannon: Bubble Man.
 * Kill It With Fire: Delay Flame (Quick Man's weapon) and Proto Charge (Heat Man's).
 * Kill It With Ice: Ice Circle (Wood Man's weapon).
 * Lethal Lava Land: Downplayed with Metal Man's stage, which has molten metal that one-hit kills you.
 * Mercy Invincibility: Averted in the Hard version. This tends to turn Nintendo Hard sections into pure Platform Hell.
 * Mirror World: Wily 6 is this to Flash Man's stage.
 * Nintendo Hard: Oh yes.
 * One Hit Kill: Za Warudo towards Clash Man.
 * Playing With Fire: Heat Man and Quick Man.
 * Power Fist: Again, Heat Man seems to have one. It glows as well.
 * Remixed Level: Again, Wily 6 is this to Flash Man's stage.
 * Shifting Sand Land: Heat Man's stage.
 * Slippy Slidey Ice World: Wood Man's stage.
 * Shout Out:
 * Flash Man's weapon is named Za Warudo.
 * Air Man's portrait on the stage select screen is taken from I Can't Defeat Air Man.
 * Several stage graphics are ripped from other games:
 * Flash Man's is from Yoshis Island.
 * Quick Man's is from Mega Man X 2.
 * Air Man's is from Kirby's Adventure.
 * Super Mode:
 * Tank Goodness: The Guts-Dozer, as in the original.
 * The Lost Woods: Flash Man's stage, as well as Wily 6 (a Palette Swap of the former).
 * Time Stands Still: Flash Man, like the original.
 * And of course Za Warudo/The World, his weapon.
 * Title Theme Drop: Done in Wily Stage 6. And it is awesome.
 * Under the Sea: Wily stages 1 (at least the first part) and 4.
 * Underwater Boss Battle: Bubble Man. Also, the Buebeam Room.
 * Underwater Ruins: Bubble Man's stage.
 * Weaksauce Weakness: Crash/Clash Man is killed in one hit by Za Warudo (a weapon that isn't even offensive).
 * Word Salad Title