I did some searching and only found a prequel to the game called Barbarian Onslaught on Newgrounds, the sponsor of both games.
There is no sign of the game developer, Johan Hjarpe, making a new 'Barbarian Onslaught' game anytime soon... he did, however, make a game called SuperFighters, which was released in June 2012, and is currently working on a sequel for this game. =)
