To be fair, Ys has its fair share of faults. The amount of backtracking is ridiculous in both Darm Tower and the Solomon Shrine. Going up the belfry twice for example. That was a bad design decision, because there is nothing else in that area that makes the return trip worth it other than a plot MacGuffin that you have to hold something up to the sky. Those things are kind of tolerable the first time, but on my subsequent playthroughs I've been genuinely annoyed by them. I just wanted to get back to populated areas and on to the fights with Dalles and Darm. Granted, at this point I have now played through six different versions of Ys I&II (Eternal, Chronicles, Falcom Classics, etc.), and the Turbo version five times now.
The layout of several areas isn't intuitive and can lead to people getting lost because of how similar things look from area to area within those two locations in particular. A map feature would have been a welcome addition.
Being forced to sit through several dialogue boxes that you've already read when you want to heal at the Goddesses' Palace is also obnoxious, and there are a number of items that don't seem to serve any particular purpose.
These same things can, of course, be said of many games. My point was simply that the game is not without its flaws. There are very good cases to be made for both games, or even for other games of that year.
Heck, Metal Gear 2 also came out that year in Japan, and there was literally nothing else like it on the market besides its predecessor (which was extremely ambitious, but unpolished). That game was absolutely visionary for the time in which it was made, to the point that Metal Gear Solid is almost a direct copy-paste job.
To be honest with you, one of my absolute favorite games from that year is Little Nemo. It's filled with bugs, glitches, and slow-down; but it also has some of the best melodies I've ever heard on the NES, and it's got some great gameplay concepts and tight controls. I wouldn't say it's better than any of the other games by a longshot, but I've also probably played it 50+ times now without tiring of it.
My main point is that much of this is subjective and there are good arguments to be heard from all sides.
