So a little late, but the demo came out in the US this week. Includes 3 stages. Pair Units featured are Reiji and Xiaomu (Namco X Capcom), Jill and Chris (Resident Evil), Kazuma and Goro (Yakuza), Jin and Kazuya (Tekken), and Demitri and Morrigan (Darkstalkers). Solo Units featured are Heihachi (Tekken), and Phoenix and Maya (Ace Attorney; yes they are treated as a Solo Unit even though they are obviously two people). Baby Bonnie Hood (Darkstalkers) is the only boss you encounter.
Clearing the demo up to three times gets you some bonus items when the full game comes out. Five to seven gets you some extra gold on top of that, and eight through ten some extra CP for powering up skills. The enemies are ridiculously weak but grow steadily stronger as you clear/replay the demo.
The battle system's been tweaked quite a bit. Biggest/most obvious change is that the turns now go by player/enemy rather than the individual unit, so you no longer have to worry about certain actions slowing down one of your units. The game now pays attention to which way units are facing for attack advantages. Normal attacks will charge if they go unused during a battle, increasing their damage for the next battle. The "hold" that Cross Hits place on an enemy can now be broken by a launching attack, which increases said attack's damage (referred to as a Cross Break). Then there's Mirage Cancel: Hit B during your attack to instantly stop and grant yourself an extra normal attack (drains the XP gauge, which is used for special attacks and blocking)
Reiji and Xiaomu are kinkier than ever, and the new Shinra engineer (who is also the game's shop keeper) is no slouch either.
Sheath, Saya's new bunny friend, is the textbook definition of hyperactive, but the demo doesn't tell you much about her. Heihachi was accused of stealing bioweapons and thus hired Phoenix as his defense attorney. Phoenix and Maya's ability to fight is actually a gift from Morrigan, who charges Maya's magatama (the one she wears on her necklace, not the one she gave Phoenix) with her own magic.
Also on DeviantArt, Rumble, DLive.tv, and the Fediverse (@freespeechextremist.com and @bae.st)