I'm pretty sure it is, I remember having the game when it first came out. I was a huge Robot Wars fan, I even went to see it being filmed a couple of times. I'm almost certain that it's the ability to play as the house robots, I can remember playing the game being Sgt Bash in some of the matches, as well as being Matilda. So, I'd say yes. If not then have a look round some sites like IGN, or Gamespot they might have the answer in it.
I wouldn't know how to finish it for you though seeming I got rid of the game.
EDIT: Thinking about it, I don't think it does actual announce the prize. I'm sure that if you go into Arcade mode it will now let you play as the House Robots at any map. Try that 👍