I think I'm going to fall on the side of "Really good, but not complete" as well, and oddly enough I think the abundance of narrative here is actually both to blame and a huge boon to the game. Early on, it's extremely narrative heavy when establishing the mission/therapist/home rhythm and overall tone, which is fine, but it has to be said that the short and simple combat rooms do feel outweighed by that story and leave you itching for more substantial action beats. Then you get to the mid game, and as the story comes into greater focus, the scenarios also get more creative- weaved into and out of fractured storytelling- and the game hits its stride. All that worldbuilding starts to payoff, more extended gameplay sequences are informed by the scenario instead of being overpowered by it, you get a few boss fights and set-pieces, etc, etc. What began with a fairly rigid structure is now breaking its own rules, and jump cutting everywhere, and dropping you into missions when you don't expect it, and building into something greater.
Then it ends.
And this is where I come back to the story being a positive but also part of the issue here. It's not that you can't have a fulfilling game at 4-5 hours, it's that Katana Zero telling this story, with this kind of gameplay escalation, doesn't get to peak. It's over just as the gameplay is getting more involved and challenging, just as the story is answering questions, and right at the point where some personal stakes are thrown at the protagonist. It's otherwise a very satisfying game moment to moment- with beautiful pixel art and animations, a great soundtrack, ridiculous dialogue through an active conversation system, an interesting core sci-fi gimmick, and super crunchy hit feedback- but if the game was going to lean on story based pacing this hard, it needed more time and variety to reach its potential. This is always a tough criticism to lob at indie games with a small team (or no team at all), but it is what it is.
Even with that caveat, I'd still recommend the game because it's real crunchy and stylish.