Oneechanbara Origin is far better than it has any right to be. And considering the last two games in this series were also far better than they should have been... Let's just say this game is very good.
You have everything you expect in a hack and slash. The cool combo system for timing the swings on your main string is there. You have an excellent dodge and an even better parry, a satisfying slowmo slide with a boost of super for timing a perfect dodge and a lovely clang and enemy stagger for a good parry. (This dichotomy of super meter and staggers for the two defensive options is a great way of rewarding successful defense in different ways, tying the games main offensive systems into the defense. Dante deserves an RG meter, but in a less technical game than DMC, this solution fits perfectly.) Enemies wind up clearly even when you're surrounded by hoards of zombies. You don't have the command moves of a more stylish game but you do have two weapons and two characters each for comboing. Everything offsets your string. Dodging, jumping, shaking the blood off your sword to reload, it all chains and keeps your main string going, which is endlessly weird but has its own charm
The enemy variety is good, with the hordes of zombies functioning as good beat em up fodder up to enemies who fight back and make you use your defensive options. Dismemberment can change enemy properties or attacks but it is seldom something you can use tactically. For the first time in an Oneechanbara game the bosses are actually good. With the combat fundamentals so tight, the bosses are great fun.
That said to appreciate it you must be the sort of person who replays action games as the game itself is quite short. There is an infinite mode, quite a few pointless grind achievements to unlock equippable rings and concept art, but you really have to enjoy the game for its own sake here. Oneechanbara Origin is easy to play for its own sake though. There is a leveling system, but it completely vanishes once you hit the level cap as the highest difficulty scales perfectly to max level characters, which makes it one of the few action games with RPG elements that actually controls them and does not let them control the game.
Few franchises love their history as much as Oneechanbara. This series started alongside EDF and began as a goofy budget game. Origin retells the story of the first two Oneechanbara games which never came to the West. Before Z Kagura and Z2 Chaos changed the tone of the franchise to comedy, these games were about a swimsuit wearing girl with a katana having to kill her sister due to cursed blood and the games played the drama completely straight. There was no reason to go back to this story but these guys put their hearts in it. The writing quality is better than it should be for schoolgirls fighting zombies. Some of the drama is a bit too cheesy and the ending is a bit of a wash, but the banter between Aya, Saki, and Lei has some decent depth to it. Lei has a growth arc over this game that I didn't even notice until the DLC missions spelled it out explicitly how much of what she was talking about was her own issues.
Speaking of DLC, if you purchase the deluxe edition, you will receive all the DLC, including several one-off bonus missions that do not really add much content but give you a few story bits and some short levels with fights, additional costumes, and songs from previous games in the series. If you view the DLC price separately, it can appear scary, but the deluxe edition has all of it in one package. Unfortunately, I believe early unlocking Lei as a third playable character is offered as part of this DLC. She can be unlocked normally if you clear 100 floors in survival mode but that is no small ask.
Having played this on console and then PC, I can say the PC port offers a far better frame rate than the console versions, though I run into some memory leak issues on PC. it's a good port besides that though. If I had to list one issue, it is that the first boss is fairly overtuned for the level you are when you first meet him. All subsequent plays will not be a problem, but on the first run he can be a bit of a wall.
All that aside, Oneechanbara Origin is paced extremely well. It is a solid action game with no bad parts, the levels don't waste your time. It is easy to play, quick to play, and satisfying to play. I can't say that about some of the best in the genre. I am excited to see where this franchise goes from here.