ボンバーマン'94体験版 / Bomberman '94 Special Version
天外魔境 電々の伝 / Tengai Makyou Deden no Den
PC Engine (Super CD ROM2)
Battle (defeat all Bombermen)
1 to 5 (battle)
1993 (Special Version)
Bomberman '94 Special Version was a limited edition game with approximately 10,000 copies produced and only given away through Hudson's newsletter and at one of their caravan tournament site, apparently (source). The release date is unknown, but one can assume it came out before the retail release.
Deden no Den was released the following year, and is near-enough the exact same game. All the Bombermen have been replaced with Kabuki Denjirou, a character from the Tengai Makyou / Far East of Eden RPG series (most of which were co-developed and published by Hudson Soft). It was distributed through the same means, and is approximated to have had 20,000 copies produced (source).
It's just Bomberman '94's Battle Game with only one character available (Bomberman in Special Version, Kabuki with differently coloured accessories in Deden no Den) and only one stage available (it features arrows that redirect kicked bombs). All items from '94 are present, including the Louies. Curiously, you can't change the other players to CPU, it's exclusively human opponents only.
To my knowledge, this only works in Deden no Den.
On the CD boot-up screen, hold Left and press Run.
Then on the title screen, hold Right and press Run.
You will gain access to four new stages.
There's a code that changes the Japanese "PUSH RUN BUTTON" and copyright details to English... but I've forgotten how to do it. Little help?
Comparisons between Special Version and Deden no Den. For the most part, Special Version uses preliminary resources and graphics while Deden no Den uses materials from the retail game.