Senior producer Jesse Caceres and art lead David Nakayama shared particular pride in how CoH has grown and adapted over the years. One of the examples they cite is their recent "Ultra Mode" upgrade to the graphics engine, which allows players to pump up the pretty visuals that would've been all but impossible in 2004. Another reason for their success, according to the pair, is that the team worked hard to provide gamers with play choices, such as the ability to roll a villain or to create their own adventures through the Mission Architect system.
Caceres has an additional idea regarding the game's longevity: its community. "I don't know if it's just the nature of our game or what, but our community is very mature... I think that kind of back-and-forth and that discourse that we have with our player base is one of the reasons why we have such a dedicated following."
You can read the full interview and glean all of Paragon Studios' secrets at Gamasutra.