The Theatrhythm: Curtain Call demo sure is Theatrhythm. You can use the face buttons and the D-pad/circle pad in order to hit notes. Using the D-Pad/Circle Pad is pretty imprecise on FMS (the field music stages -- which is the FFXIV stage in this case), so it's best to stick with the stylus on that one. Sometimes the stylus does afford better precision on Ultra mode, but it depends on the person. Sometimes I can get by no prob with the buttons on Ultra, but sometimes I can use the stylus for that. Ultra mode in this game doesn't seem to fuck around compared to the previous game's ultra mode, which is a good thing.
The demo has its share of Lightning and Lightning Returns, which is no surprise. You have Lightning as the lead of your party, the demo's tutorial screen shows the Lightning Returns page for the tracks listed, and you start off on the LR page. You have access to three songs with all three difficulties (plus a practice mode + watch the game play itself mode): Seymour Battle from FFX (which... sounds... unremixed?), Crimson Blitz from Lightning Returns Final Fantasy XIII, and Serene Forest from Final Fantasy XIV: A Realm Reborn. The characters you're dealt are Lightning (in her LR outfit), Tidus, Yuna (in her FFX-2 Gunner outfit), and Yshtola (from FFXIV).
It's... still Theatrhythm? I like Theatrhythm, but I still had a few issues with it as I'd brought up in the original game's OT. The characters don't say anything witty or funny before proceeding into the stage like in the last game (they just have facial expressions), and I think that's beneficial. There was no EMS stage (that one stage where you play the songs and you watch CG) so I don't know how well that is going to be executed. A little disappointed we didn't get stuff from XIII-2, but w/e.
Why they chose the songs they did for the demo is beyond me since there are much better tracks from each soundtrack, but I guess they chose the more... famous ones? I dunno about XIV's selection. I'd have chosen something different. Still funny that they chose the Seymour Battle theme even though that was in the last game.
Demo has 30 uses.