I may not be able to play old Flash games in Newgrounds anymore, But thankfully BlueMaxima's Flashpoint program has that all covered. (Not sure about getting the Newgrounds brand reward medals? Go research Ruffle.)
As I play this game, I continue to think of what a sequel would be like? IF there would ever be one.
I imagine the sequel would have double or triple the number of player characters. Featuring well known characters. Such as Doki and Nabi from the Acclaimed "There she Is!" mini series. And Alpha and Flame girl from the T.O.M.E. series. At the same time, The sequel would feature character's not many would remember. Such as Alice and Cage from the "Rats on Cocaine" Series. And Mike and Satan from the "Erik the Juiceman" series. Not to mention there could be new game mechanics and battle arenas. No different than how Super Smash Bros. makes itself better and better over the years.
I know this comment is wishful thinking. But Newgrounds is Still a great website! And this game is a good summery of it during the 2000's.