According to the official web site for Plasma Pong, the download link and information page for this freeware game had been taken down until further notice.

The forums are still up, while the game itself can be acquired from Download.com and CHIP Online. Both Washington Post and Gamasutra interviews had revealed that a multi-player version was in the works before this setback.

Apparently you can't do a Pong remake without approval from Atari it seems.