Yesterday I finished my solo playthrough of this game. I made a big push this last week and weekend. As of today I am no longer working from home, and I wanted to finish as much as possible before resuming my commute.
This was not as intensive as Dragon Warrior III, or even II. I went to max level in both of those games; this one I finished at level 47. Doing it at a lower level added to the challenge to keep it interesting, but at much higher levels I think this could get pretty easy. The most interesting part of this was learning about boss regeneration values, which are not as well documented as they are on Dragon Warrior III despite this game having more bosses with background regeneration. It was fun to try this game's different item and spell sets to find the right combinations for beating regeneration on the bosses.
I mentioned before that, for reasons I can't really justify, I stepped on each square in the game. I no longer clearly remember what ever possessed me to do this in Dragon Warrior I. In some ways made more sense with I and II, which have a steeper EXP grind anyway than the future games. But, as one might expect, it was kind of ridiculous in III and IV, which have much larger worlds but a tamer EXP growth curve, as well as endgame metal enemies with much higher EXP yield. Whatever compulsion made me keep going with this, since I'd done it previous games, I'm confident I won't ever feel the need or desire to do this in any other game.
I also went back and finished off my 100% game file. I am pleased to say I found everything in this game without using a guide (other than to confirm I actually had everything). I also updated equipment and monster lists I've been compiling to track recurring items and monsters in the series.
I've decided that what I've got done is enough for me to move on to Dragon Quest V as my main game, which I started last night. I will still do my challenge quests/comparison playthrough of Dragon Quest IV, as I have energy, but my main focus will be V. I've been wanting to replay it for a long time, and have tried restarting it twice before. I think the time is finally right where I can give it the attention it deserves.