Prototype fans thought protagonist Alex Mercer "was a dick," developer Radical Entertainment has said.

It hopes the main character of Prototype 2, James Heller, will be likeable.

In Prototype, scientist Mercer gains destructive superpowers from a virus he himself unleashes on New York. He then goes on a revenge-fuelled rampage in an attempt to uncover the truth behind the catastrophe.

In Protoype 2, you play James Heller, a US soldier who blames Mercer for the death of his wife and daughter. He gains superpowers himself after a revenge-fuelled pursuit of Mercer in a crumbling New York city goes wrong.

"Some people literally came out and said, 'Man, Mercer was a dick!'" studio VP of technology Dave Fracchia told Eurogamer.

"For me, Mercer was still pretty cool. I'm an ex-scientist myself and a thinking kind of guy. Maybe not so much a socio-path like he was."

Despite Mercer's off-putting personality, Prototype, which released in 2009, struck a chord with gamers and went on to sell 2.1 million copies.

Its success helped convince Radical's overlords at Activision to invest in a sequel, providing the developers at the studio with an opportunity to improve on their openworld superhero action game.

In order to make Prototype 2's Heller likeable, Radical added depth to his character - something Fracchia admits Mercer lacked.

"I like characters that are interesting," he said.

"They don't have to be good. In fact, most interesting characters are conflicted good and bad. Even Heller, he's gone to the point of wanting to go after Mercer, so it's almost like to the point with post-traumatic syndrome that it's unhealthy how much he just wants to go after Mercer.

"He's got his own depth and things he's gone through. And of course, the loss of his family is a very dark thing to go through. We wanted an emotional connection. In many respects Heller's more likeable because of his depth."

But what of grumpy old Mercer, who pops up in Prototype 2 as quasi-ruler of New York and with an agenda of his own?

"With Mercer, you're seeing some depth we're putting into him," Fracchia explained. "We're getting a chance to see into the mind of Mercer at this point.

"For us, it was just getting into better storytelling. That's what it comes down to. You have to have depth. The likeability comes from that depth. You could like characters that are, quote unquote, bad, because they're not necessarily doing what they feel is bad, and they're interesting."

Mercer isn't the first video game lead character to called a dick, of course. Remedy told Eurogamer Alan Wake was intentionally "a bit of a dick" in a 2010 post-mortem interview.