Is this the mod you used as the model?
(click to see more info)
Description: This is the game of Spleef - multiplayer edition. If you want to play this game, change the two text variables in the SetupMulitplayer function to be your Minecraft Username and your friend's Minecraft Username. You will have to open your server and have your friend join before running the mod.
Have you tried keeping what's in the black js blocks (in the main function)?