Rockman no Constancy is a very extensive ROM hack of Mega Man 2, with changes to the music, the graphics, the level design, and the characters. A couple of the powerups from the original game remain, which means that a number of techniques that can be done there can also be done here.

Two versions of this hack exist: "normal" mode and "hard" mode, with the primary difference being no mercy invincibility on hard mode. CUI and warmCabin here play on "normal" mode and improve on the previous "normal" run by 31.73 seconds by including even more zips than before.

WARNING: There are instances of flashing lights during and after the Wily Stage boss fights, which may cause epileptic seizures to people affected.