This is the game that started the dragon quest(Dragon warrior in the states). You are a lone hero who sets out to defeat the evil dragonlord. While it may seem a bit dated by today's standards, so much of what has made the DQ series enjoyable is present here, right down to the deceptively smiling slimes.
The game play is relatively simple, kill enemies get gold/exp, level and buy equipment. There are many places to explore, caves, towns, ruins and the dragon lord's castle itself.
As I said in an earlier review of dragon warrior, you need to speak to the king in starting castle to save, when you cross bridges the enemies will become stronger (and bring stronger rewards for their defeat) Torches are needed while walking in caves early on, while you do gain a light spell it's best to save the mana for healing or the offensive burst if needed. Swamps are another problem you'll take minor damage crossing them, as well as barriers(green dotted squares, and blue with diagonal lines). One of the hardest parts of the game is due to how saving works, it makes traveling a bit more dangerous and much work can be lost so always carry a chimera wing, that will zoom you back home.
Towns have shops where you can purchase equipment, items and find a place to sleep/heal (inns usually). I've always prefered doing a little extra grinding for the 2 step increase in armor and weapon, as well as using caves to "farm" items and gold.
As far as items, medical herbs heal, antidote cures poison, torches cast light (tho light spell creates a bigger circle) the water is useful for preventing random encounters of monsters that are weaker then you are.
Overall If you are looking for a good oldschool jrpg, you cannot go wrong with this game, in fact nintendo power once had Dragon warrior as a give away for a subscription, along with maps and a strategy guide, a wise move considering this was my starting point for 20 some odd years of playing role playing games.

After reading this review i think i am going to give this game a try, i had seen in the rgr earlier when i was browsing and thought against it, thanks for the great review, hope it is as good as it sounds.