Fida Puti Samurai is one of the most unique games I've ever played, which is ironic since there might not be an original bone it its body.
On the surface, it seems conventional. There's an aesthetic based on late-90's nerd culture with an emphasis on internet pornography, but mostly on the parts that became so widespread they've gone from esoteric to popular to played-out. There's roguelite gameplay with secrets, perks, and collectibles. There's boomer shooter movement with a main character who spends the whole game screaming angry one-liners. For someone who normally doesn't care for any of that, I'm surprised I liked this. But the more I played, the more bizarre the game felt, and in the end I decided that my initial idea was correct all along:
Fida Puti Samurai is the video game equivalent of a giant doodle, a drawing that the artist made with only partial effort but then kept adding onto with whatever seemed like a good idea at the time for hours or days or weeks until they were bored. The end result is "deeply characterful" at the same time as "mostly nonsense". At first I got that feeling because the game seemed like an assemblage of things the developers liked edited to fit together in some barely-justified way but then I got the same feeling about the underlying gameplay systems and I became somewhat conflicted.

Let me try to explain.

The gameplay loop is easy to grasp. You start in a cyberpunk back alley made of randomly-assembled city blocks populated by randomly-chosen stores full of supplies and covered in a layer of enemies. There may be a perk store. You shoot your way through and reach a handmade level, then shoot your way through that, secret-hunting and gun-scrounging all the way, until you reach another cyberpunk back alley. Repeat until you get to a boss arena. Then spend some time in an interlude zone and move to the next area, with a new collection of cyberpunk streets and a new set of pre-made levels to clear. Fight the second boss, do it all again, fight the third boss, reach the end of the current chapter and get some shakeup for the next chapter. That is a complete run and it takes around 45 minutes or less.
During the levels, you get money by killing people and finding stuff. This can be used to buy perks and upgrades for that run at the upgrade store, or it can be put in mailboxes to send it back to your house (where you stay between runs) and set a checkpoint to let you start your run midway through. At your house, you can choose a weapon to start future runs with and armor to give you various boosts and you use the money to pay for those and for collectibles you find that give you slight permanent upgrades.
There's a LOT more to it and by the time you reach the end of the game you'll still be finding entire new features, but that is the core of it and everything else is basically an accessory. It's fun and simple but leaves a lot of room for experimentation and surprises.
For an example of how bizarre this gets, though, let's talk about money. In a run, the most valuable thing you have are your weapons. They are not made equal and they have strengths and weaknesses and use different kinds of ammo. To be effective, you need a variety of good ones so running out of one kind of ammo doesn't screw you. You get the best ones by finding secrets while playing levels, the ones normal enemies have only stop being inferior in the last arc. The second most valuable thing is perks, which are bought with money, which you get by playing levels. In other words, USING a checkpoint is bad since the run is more likely to succeed in the last arc if you do more stuff in the first arc rather than skip it. Odd, considering this is one of the few mechanics with actual tutorialization.
The fact that some weapons are far better than others causes problems. In chapter one, which weapon you bring is significant because it defines what you'll be able to do for the entire first third of the run or more. Bringing a melee weapon is safe but means you lose out on the best guns. Bringing a powerful weapon with bad economy might mean rationing ammo early on. The sledgehammer, however, is both a good melee AND lets you find a lot of secrets that normally require the rare and powerful dynamite, while a few guns are simply too good to pass up, so the decision soon narrows itself down dramatically. Then even that question goes out the window since at the end of each chapter you get an upgrade that lets you bring an extra weapon into the level. By the fifth and final chapter, you have four weapon slots and can start each run with ALL the best weapons AT ONCE.
The difficulty is another weird design choice. To "get" it I read someone else's review and I finally understood why the game is laid out how it is. The later chapters "increase the challenge" by making enemy spawns inconsistent and weird because the challenge is supposed to be you memorizing them even when there's a lot of possibilities. Except you can't change difficulties mid-save-file and on the first four difficulty levels out of five you can get by on reaction speed, so for most players this nuance goes completely above their heads... with a problematic result.
Going back to upgrades, they're the reason the difficulty curve trends DOWN as the game progresses when playing anything besides the hardest difficulty. Having 105 max HP instead of 100 isn't a lot, but what about 130? What about getting more ammo from every pickup? What about making armor more efficient? And, of course, there's starting every run with all the best weapons, making every fight easier and letting you plunder every secret for endless hp/armor/cash, and buying unlimited perks once you run out of new guns to spend your spare dollars on. Luckily most perks aren't actually that good.
Even the story is bizarre. You start off chatting with your boyfriend, but he stops showing up even before you beat chapter one. Then you spend the rest of the game hanging with the titular Fida. Your character has a lot of great one-liners with great delivery only for the entire story to be lame and delivered through text chats and voice bips exchanged between you and a ♥♥♥♥♥♥ cat. It's not like there's no more questions to ask your bf.

If I didn't like the game, I would spend a lot more time on the design choices that, in a polished product, would have been cut, like the most unique weapon being terrible and the interlude shooting gallery being far too rewarding, however, I think that you're looking at this game because you're an enthusiast, and as an enthusiast, the baffling ideas at play here have to be seen to be believed and understood. The truth is that the game is entertaining and soulful, it's just also confusing.
7/10, there's a fan-made h-patch but I don't know if it's any good.