Wow
This is like... Newgrounds Rumble before Newgrounds Rumble was even thought of.
Great concept. Old game, as I can easily tell, but a classic, as well as an addicting game.
Idea:
Make a sequel, named "Portal Kombat"
Add characters from "the gang" (the picture on right on the Flash Portal page) as well as Newgrounds Rumble. Add better controls... and, well you have yourself a winner.