When we boot the US version, right off the bat we notice that the opening Masaya logo has been removed from the North American release, though the NCS logo is retained and the copyright year is updated from 1989 to 1990. Otherwise, it's identical.
And of course, the language on the level select screen has been translated from Japanese to English, though the localization is on the lazy side. The PC Engine version appears to have interesting, unique names for each dungeon, while in the U.S. we just get DUNGEONs numbered 1 through 22.
The game has an Eastern sense of humor that survives the translation process -- we start out with a dagger for a weapon and a pan lid for armor. The translation does make the game's rapid-fire status messages much easier to deal with, although most of the text is non-essential, along the lines of IT'S A DOOR!, so it's not particularly difficult to play the game in Japanese. But it's a little easier to tell what's going on in English:
As far as I can tell, Double Dungeons' gameplay is exactly the same in both territories -- same enemy creatures, same maze layout, same difficulty level:
And the gameplay is very much the same as most early games of this type. We walk through the 3-D dungeon, mapping out our route on graph paper if we wish to be compulsive about it. We take on various flavors of nasty creature, risking our leaves to earn experience and gold. And we visit the shops to buy better weapons and armor, wondering how this bubbly young lady manages to survive amid the death spiders and poisonous blobs:
And of course, occasionally we take too much damage and die, which sends us back to the start of the dungeon with our level and experience points intact, and a full complement of hit points, but no cash. There's no real game-over point -- every time we die, we just get sent back to the start of the current maze, though we can intentionally quit and receive a password for later continuation.
The game takes its name from its one innovation - it features a two-player split-screen mode, if you have a friend who wishes to traipse through the dungeon along with you. But the players remain invisible to each other -- the two warriors are just working in parallel within the same map, starting at different points, and there's no real cooperative or competitive fun to be had beyond seeing who can beat each dungeon the fastest.
I remember looking forward to this game back when it was coming out for the TG-16, but I somehow never got around to buying it until recently -- if I recall correctly, the early reviews were not particularly positive. Looking at it today, Double Dungeons suffers from its simplicity -- it's fun to engage in maze-based RPG combat for a while, but not for days on end. So many games since have done this sort of thing better -- there just isn't much to do beyond grinding for levels, the mazes all look the same, and the experience wears thin quickly.
Still, it made it across the ocean, symptomatic of NEC's interest in bringing games they perceived as "Western" over to the TurboGrafx-16, while many of the best PC Engine games stayed in Japan.