Rumble-4-ever!
Now, you've done a good thing. Honestly, this is one of the best games I ever played on NG. That however doesn't mean that it's perfect, nothin' is. Now I'd recommend you add some more extra features, plenty of new battlefields and such. Also, I'd be sure to include some other classic NG characters (Strawberry Clock, and Joe Zombie come to mind...). And Henchmen... Make 'em playable as well (Hey why not? I mean you could make it like it can respawn 10 times or so before it's gone for good, only avaliabe for the versus mode or something).
As I said before , nothing is perfect and it's always a matter of wheter you can make it better. Now it might sound weird coming from a guy who's never made a single flash thing , but seriously it is not my area of expertise. You guys on the other hand gotta be among the best of the flash artists on the face of newgrounds, and you know the best for your art and all that, but you know, I tend to have good ideas of my own (at times).
Well, anyways, I've already written a lot as it is. Do I have to write a conclusion? I didn't think so. Awesome game, and keep it up...