I finished a playthrough.
Alternate paths still exist but multiple endings are gone. Regular playthrough is called Chapter 1, the equivalent of Nightmare is called Chapter two, it seems to go up to 4 chapters and there is another option below, there's some space in between the last option as opposed to the other 4 which are all close to each other so I more or less expect it to be some sort of extra mode with the main story being 4 playthroughs long.
Zangetsu starts off like his basic counterpart in 1, you get Dominique clearing chapter 1, Sniper clearing 2 and Doggo in 3, the boss of chapter 4 gives Zangetsu an weapon that upgrades his kit and gives him a triple slash regular combo, his downward slash from the first game and all of his sub weapons get upgraded, talisman and chain gets extra Y axis range, his aura powerup gives him a spinning aerial attack, you can still get the downward slash if you hold down and attack while airbone but in general you're gonna just wanna use the upgraded version. Haven't checked to see if there's extra damage to the power up and other subweapons, also I think his regular non upgrade aura doesn't carry to teammates while the upgraded one does, I'm not sure when I'll ever touch base Zangetsu again so I won't bother testing.
Dominique plays like a female Lecarde, high jump, can bounce on people with spear, has extra range but lower attack speed and can attack upwards. Her subweapons consist of one tornado that goes straight and falls downwards while travelling through terrain, a thunderbolt that goes up and then travels through the ceilling killing everything, she can throw a seed that grows into a life recovery item and golden candles drop a one use subweapon for her that can ressurrect your whole party and cure all of them for a certain amount of hp the downside is that it has a really long casting time but you can use it outside bosses so it's still really broken(specially for a particular reason that I'll list below) and there's one subweapon that makes her do an even higher jump which is mostly used to reach places you wouldn't be able to. She more or less is the paladin of the equip, her specialty to get through certain segments is her high jump and bounce on mobs/candles to reach certain places.
Sniper works like the old man, he's pretty terrible as playable character on his own so you'll just whip him when you need him for specific uses, has the lowest hp out of the cast, his regular weapon is a hitscan weapon so it's pretty great to wipe weak trash from far however his weak damage paired with a insane recovery speed(he reloads after each shot) makes its usage pretty limited. His subweapons consists of two javelins he throws diagonal up, one axe-like grenade that rolls on terrain until it hits something or bounces back on an wall and a power up that drains your mp each second but allows him to attack at a much faster rate giving him one of the best dps in the game while he's powered up. He more or less fills the role of a sniper, you'll use him to take things from far away but that's about it. He can wall jump and crawl to get to certain segments.
Based Doggo has the highest hp value in the game, has slow attack speed but hits hard and has a decent hitbox, also has aerial attack that involves him falling into the ground and smashing anything below him, it has no armor or iframes so you gotta make sure you'll kill whatever you're landing on. Like Gebel he only has 1 subweapon so switching to him and breaking subweapon candles will net you more mp instead, his subweapon is a buff that drains mp each second but makes him invulnerable to any sort of damage except pitfalls and certain traps. He's the literal tank of the party, you'll be using him a lot to traverse through terrain since he's sturdy, immune to certain traps like poison and spikes, he also can hover making him the character with the most air mobility in the game after Dominique, he can also tank most of the stuff with his subweapon so there's that. He's used to break floors, metal doors, reach places with hover, places where he can walk through without taking damage and get through mobs that never stop attacking(like the archers from the first game) with his buff.
Okay now onto more details about the game itself, it's pretty similar to the first one,there's a total of 7 stages, no multiple endings but apparently there's 4 or 5 campaigns. The first one is pretty basic and acts like the tutorial for the game, the first few bosses won't even suicide attack because your new party members will kill them before they can do anything. Chapter 2 is like Nightmare, you start as 3 characters to save the fourth one again, the first few bosses now will do their suicide moves, you have access to more routes now on the first few stages and bosses are much harder like the first game.
My gripes with the game itself is that unlike the first one, it doesn't seem like the game was designed around people doing challenge runs in mind, you can't even have basic Zangetsu as you're forced to get the whole party and so doing any sort of challenge run with a single character becomes a hassle(as you have to wipe the other characters to get a retry). Also the enemies and stages don't seem designed like the first one where you should be able to get through anything even if you're down to 1 character and has no mp. I did a no subweapon run with basic Zangetsu on the first game and as long you're not going through alternate routes(which you shouldn't be able to if you're playing solo Zangetsu) everything was doable, I'd go as far as saying the game was (mostly)doable with no subweapon Albert alone if you put enough dedication into it, in this game however it seems like they're putting more focus on pushing your whole party to the limit, there's more than a few segments that from a first look, they just seem impossible to do certain characters, specially the Sniper guy, though who knows I have the game for no more than one night so things might change in the long run, the game is harder after all so maybe it just needs more lab time.
As for actual complaints, checkpoints are now much farther from bosses, if only a character dies you get to restart from closer(though you get to deal with a single segment that's usually filled with way more annoying mobs than the first game) but if you lose all 4, you restart from pretty far which can be pretty annoying and contributes more to what I've said about the game seemgly not being designed around a single chracter anymore. To compensate for this, bosses start with less hp the more you retry without losing a whole life(your whole party), this is either a plus for some people or an actual offense to anyone wanting to kill the boss without handicaps and would rather just retry from a closer checkpoint(I'm the latter). Some mobs also have been designed to be worse like the fat flying pigs, now they explode on hit as opposed to before so that simply means you have no real way to deal with them if you're stuck with someone that isn't sniper and has no mp left. That being said I've only met them once and they might've been or not on a segment only the Sniper can cross so maybe you ARE supposed to have a ranged option, either way I like them better the way they were before.
These are early impressions, keep in mind that the game has at least 3 more modes and I haven't finished Nightmare yet so these aren't final yet. Also worth mentioning that I do like the bosses in this game way more than I liked the ones from the first game, it's just the new checkpoint system that annoys me.