Mugen Senshi Valis (remake of the first game) is a must for PC-Engine. Valis 2, 3 and 4 are also great - they're all japanese but language isn't an issue. Cadash, the Bonk series, Neutopia, Son Son are also great games. Also, Mega Bomberman on the Genesis is a port of Bomberman '94, and the later is better.