"Welcome aboard, Johnny Sins"

Yep, that's pretty much spot on.

Tonally and thematically VP1 and CotP are very similar and much closer to each other than they are to VP2, although the structures of their storylines differ quite a bit.

You don't need to play on Hard to get Ending A. Normal works just as well.

There is some content locked behind Hard, most notably, the most devilish dungeons and bosses the game has to offer outside of the Seraphic Gate.

Edit: if you liked VP1, I very much recommend Valkyrie Profile: Covenant of the Plume. It's a very underrated game that hits many of the same highs, oftentimes even better.

I don't think there was a marriage between a game and a system as perfect as with The World Ends With You and the original DS.

The game has been rereleased on multiple platforms since then. And yet it's nearly universally accepted that if you can play in on the DS/3DS, you should.

For instance, one of the main themes of the game is that you can't do everything on your own, so you need to trust and work with other people. And so, TWEWY uses both of the console's screens and makes you battle with both the protagonist and his partner at the same time — a very unique system.

It works even better on the DS, because the stylus gives you the much needed precision even on an otherwise unimpressive touch screen. This is one of the main reasons the original just plays much better than the ports.

The game also tells you to expand your world by interacting with others — and implements a rudimentary StreetPass-like feature, several years before the actual StreetPass, that rewards you for meeting other people in real life.

Along the same lines, it encourages you not to spend all the time playing it. So another type of reward you can receive basically requires you to turn the game off and go touch grass.

It also has an interesting food mechanic, that only allows you to eat a couple of heavy dishes per a real world day. You can snack all you want, but the only way to raise Attack and Defense are the big food pieces. So you'll have an easier time if you take your time with the game, take breaks and properly raise these stats, although that's by no means required.

Of course, it also uses the console's other features in more conventional ways. Some of the attacks you can use, for example, utilize the microphone, and one mini-boss requires you to put the console to sleep.

And yeah, it's just a super cool game overall. Many enthusiasts consider it to be the best on the system. Amazing gameplay with tons of variety, great plot, fun characters, really good postgame to sink hours into.

To add my own take, I think Umineko is actually the greatest visual novel. But DGS2 is a respectable choice.