
Got it. (and a Vita too)
I was only able to play it for about 2 hours last night, so this is by no means a "review". These are only very initial impressions, but here's what I think so far.
GAMEPLAY - Exactly the same as Ys seven. Dash instead of jump, changing characters, special abilities all work exactly the same. Only addition is a guard button (not sure what that's for yet

). The same system of collecting minerals and fauna is also still here. Basically, this is Ys 4 done Ys seven style, so if you liked Ys seven you should be very happy here.
STORY - Doesn't follow Dawn of Ys very closely at all, and probably not Mask of the Sun either (to the best of my memory since I only played it once, in the early '90s). Adol has amnesia for some reason. The first dungeon is a cave at Puroma rock, with the music from the first cave in Dawn of Ys, before you even can exit Puroma rock.
MUSIC - Nothing but familiar tunes. I really hate to say it, but I think the arrangement could be a little better. This is definitely not Oath in Felghana level (though that would be expecting a bit much). Nor does it sound quite as good as seven to me, either. As in most recent Ys games, the really good arrangements are reserved for certain key tracks, and the rest are the usual cheap synths Falcom tends to use (if not maybe slightly worse than usual so far). Only two decent tracks so far were the opening sequence (brand new music) and the first field music in the area outside Puroma Rock (not the same as PCE. They chose to use the music which was used in the rainy stage in the PCE). They're good, but neither of these really blew me away either. I fought a boss already (which used that Malmsteen rip-off track) and the arrangement I found rather disappointing for a boss track. The Puroma Rock music is okay I guess. Keep in mind I still haven't heard much of the soundtrack so who knows? The rest could be excellent for all I know, but honestly, not too impressed so far. It's par for the course at best. I'm sure there are lots of good tracks yet to come, after all they have good source material to work with.
(EDIT: And just a minor gripe - some of the sound effects are a bit annoying too, though most are the same as seven.)
GRAPHICS - This is where I'm most disappointed. I already said I wasn't expecting much in my second post above, but I was expecting better than this. To be fair, I haven't really played any other Vita games yet, so I don't really know what a Vita game is supposed to look like, but I expect more from a system released in 2012 (EDIT: Okay, Dec. 2011 in Japan). It isn't that the 3D environments are simple - I was expecting that - but seriously are polygons supposed to be this jagged, aliased, and low res on Vita? Sorry, but it looks like a slight incremental upgrade from Ys seven on the PSP at best. The Ys games released on the PC look a lot better than this. It shouldn't be that hard to make the polygons look smooth on a system this new, and they failed as far as I'm concerned. I've seen better looking 3D games on smartphones. I'm gonna get Uncharted over the weekend so I have another Vita game to compare it to, but if this is what is to be expected from the Vita then Sony shouldn't have bothered releasing a new portable at all.
Sorry to sound more than a bit negative about the graphics and music above. I really want to love this game, and I'm sure I will get plenty of enjoyment from it, as I mentioned the gameplay is fine. Playing through another Ys seven will be plenty of fun, and it will continue to be interesting to see the new takes on the Ys 4 story, locations, and music. If you liked Ys seven, then I think you should get this game despite my gripes above.
Edit:
Correction. The town I referred to above as "Puroma Rock" is not called Puroma Rock in this game. It is referred to as "Casnan". I'm not sure if it is supposed to be equivalent of Puroma Rock, but it has the Puroma Rock music and it is the town you begin the game in.