Unfortunately, that mechanic was sadly scrapped. As for the Tokyo Toy Show '90 build of the game, I bet it's locked up someplace at Sega headquarters.
Also, through the magic of www.youtube-mp3.org, mp3cut.net, and Windows Movie Maker, I whipped up a couple of YT vids of two of the music tracks featured in Hi-Ten Bomberman, which was only ever showcased and played at the 1993 Hudson Super Caravan in Japan. For more info: http://bomberman.wikia.com/wiki/Hi-Ten_Bomberman
Battle Start Fanfare: https://www.youtube.com/watch?v=jET1w6gVCmI
Victory: https://www.youtube.com/watch?v=6swtm6ja8C8
Also, through the magic of www.youtube-mp3.org, mp3cut.net, and Windows Movie Maker, I whipped up a couple of YT vids of two of the music tracks featured in Hi-Ten Bomberman, which was only ever showcased and played at the 1993 Hudson Super Caravan in Japan. For more info: http://bomberman.wikia.com/wiki/Hi-Ten_Bomberman
Battle Start Fanfare: https://www.youtube.com/watch?v=jET1w6gVCmI
Victory: https://www.youtube.com/watch?v=6swtm6ja8C8