PlayStation Warhawk sequel. In his three-year stint (1996-1999) at Sony's (now-defunct) 989 Studios, Duggan worked on a number of unreleased projects, one of which was Warhawk 2.
Concept art listed on his profile (pictured above) paint a very different picture for the planned sequel's visual style in comparison to what eventually became Incognito's Warhawk on the PlayStation 3. Sure, Warhawk is a lot of fun now... but imagine if you could pimp into battle with a flying version of The Homer or Spider-style hawk that would make Jon Peters proud. Someone start a DLC petition, stat!