If you're an old person, then you were probably an established Mega Man fan by the time Mega Man 4 hit the NES in 1991. Maybe you even remember game magazines calling for Capcom to pack up the series because Robot Masters like Dust Man and Toad Man supposedly indicated the company was completely out of ideas.
Pfft. Dust Man. Whatever hack kid designed that joker probably grew up to be a real nobody.
While the ancient practice of jabbing at Capcom for "running out of Robot Master ideas" is silly (the company recruited children as designers specifically because kids' imaginations offer up boundless creative horrors), Mega Man 4 is a divisive game for valid reasons beyond "lame" Robot Masters. Compared to Mega Man 2 and 3, getting through Mega Man 4's stages is less about finesse and more about absorbing damage. The Mega Buster is also problematic, as its super-charging action is probably the reason so many of Mega Man 4's low-level schlub robots are engineered to suck up a lot of bullets.
But there's nothing wrong with Mega Man 4's graphics and sound. Easily one of the best-looking NES games of its time, Mega Man 4 features tons of huge mid-stage bosses and some pretty cool backgrounds. It also has a great soundtrack that unfortunately tends to get overlooked in favor of classic tunes from Mega Man 2.
Mega Man 4's music, which is composed by Minae "Ojalin" Saito (who went on to make music for the original Breath of Fire for the SNES, then returned to her roots years later to help with Mega Man 10's soundtrack), leans heavily on rock. The proper response to this observation is "Well, duh, it's a Rockman game," but Mega Man 4 really pours on the drums and guitars, all of which blare at you in true NES chiptune fashion.
To this day, hearing Skull Man's theme, Bright Man's theme, or Dive Man's theme makes me want to get up and get down. And Mega Man 4 has my favorite Robot Master boss theme, bar none. The game makes epic use of all the NES's sound channels (though the "wawawawawa" of Mega Man's charging Mega Buster tends to override everything else. Sigh).
Mega Man 4's high-energy music only makes Dust Man's theme stand out more. Though the tune plays at around the same tempo as the rest of Mega Man 4's rock, it has an experimental sound that makes it feel darker and weightier next to the rest of the game's soundtrack. The warbling effect at the start of the song is certainly memorable, especially since it's exclusive to the very start of the stage. No matter how long it takes you to work through Dust Man's domain and maneuver around its damnable garbage compressors, that opening warble is never repeated. It's pretty special.
Junk yard levels are to Mega Man games what sewer levels are to RPGs. You can count on seeing them often, and they're usually forgettable. Not Dust Man's stage, though. The whole area has an unsettling vibe that bizarrely reminds me of the old film projector movies I watched in school before VCRs became widespread.
Did Capcom purposefully design Dust Man's stage to be creepy (Mega Man is walking on a bed of scrapped robot parts, after all)? Or was it a lucky design fluke? I don't know, but at least I have Dust Man's theme to keep me company as I think about it.
Something else to think about: Dust Man's theme is the basis for Let There Be Light, one of the best game music remixes ever constructed. Poor Dust Man. He's eulogized as the lamest Robot Master, but he's indirectly responsible for so many epic things.