I think you do mean Dungeon Explorer
or it's amazing sequel, as I recall seeing something about a japanese segaCD version of it
if that's the case, it's DE2, the game for the turboduo
it plays like Gauntlet but with more story and RPG elements and a real ending (perhaps like console versions of gauntle)
you run a strange top down veiw with a character that can rapidly shoot weapons you normally don't throw like swords and axes, and you can cast magic spells, too (one black and one white per character)
best music, too
it didn't come out in north america though...not for sega consoles, just turbo
hmm
gamefaqs.com lists Dungeon Explorer as a SEGACD game, but has no info on it...
http://w3.one.net/~boland/games/segacd.shtml says DE was released in america...
as well as "Dungeon Master 2: skullkeep"
http://ryangenno.tripod.com/sub_pages/SEGACDreviews.htmsays the TG16 version is better...