First person dungeon crawling adventures and me go WAY back. I love them. Probably my favorite genre, especially those that allow you to control a single person (I view everyone extra as just stats and equipment mules). While not a single party first person dungeon crawler, Shining in the Darkness is still quite awesome. I can overlook dealing with extra characters in my party as they do more than just hold stuff- they have personality and contribute to the story as it progresses. Sega did good.
For those that are new to first person role playing games you are either in for a treat or are going to be bored to tears. You see the game world from the perspective of the characters you are controlling. You are usually limited to moving one full square at a time and turn in full 90 degree increments. Enemies are unseen until the encounter occurs and you are usually left bereft of supplies. Difficulty in dungeon crawlers like Shining in the Darkness is usually set quite high also. You are not going to plow through in one sitting. Also, grab some graph paper and keep maps handy (or just look for them online) as most of the dungeons will easily confuse you and get you turned around making you easy prey for the enemies.
Shining in the Darkness was the first in the series to be released on the Sega Genesis. We would not see a return to turn based dungeon crawling until Shining the Holy Ark on Sega Saturn. Shining Force, Shining Force II and Shining Force CD were all turn based strategy games- a major departure from Shining in the Darkness.
Sega has re-released Shining in the Darkness in the Sonic’s Ultimate Genesis Collection for Xbox 360 and Playstation 3. If you prefer true retro then grab it on the Sega Genesis on Ebay (affiliate link).