It stands to reason that if you were to develop a military-grade drug that allowed assassins to see the future and slow down time, this would manifest itself in a VHS aesthetic in your neon-soaked dystopia. Obvious really.
In Katana Zero that's exactly what you play through. As a robe-wearing, sword-wielding assassin, you experience future possibilities by playing through a level and rewinding to the start should you die. If you make it through without dying then that's considered what actually happens and life goes on.
Really, it's justification for a Meat Boy-esque ability to restart over and over at each death without having to come up with a reason why your character is respawning. Can't respawn if your deaths were imaginary. Your abilities are down to the drug Chronos, and the plot delves into its use during a war and the lasting ramifications. You visit a psychiatrist between missions who you'd think should be helping you deal with the nightmares that appear to be coming to you in CRT form, but instead he gives you more drugs and sends you off to kill people.
The other benefit of the drug is slowing down time, which is pretty handy when you've got a sword and a bunch of goons between you and your target have guns. If you slow down time, you can swipe your sword and hit bullets back at the person who just shot at you. I expect they're pretty surprised by the turn of events but they're usually too dead to ask.
You have a nifty roll move for dodging and you can pick up and throw objects. When you mix them all together you can get an amazing flow of movement through the levels. Slicing and dicing your way to victory or accidentally rolling into security lasers and restarting the level.
Katana Zero has a dialogue system similar to Oxenfree's. If you're impatient you can respond during a red part of a conversation bar, possibly angering the person you're talking to. If you wait, you'll get some normal options, but whatever you choose may have an impact on the future. Early in the game, you chat to a hotel receptionist, if you're nice to her your exit from the hotel after the mission is completed is easy, if you got on the wrong side of her she rats you out to the police and you have to fight your way out. It might be worth your while paying attention to the conversations you have with the psychiatrist…
On top of the branching elements of the story, you can also find alternative swords. A certain blue hilted sword may be quite familiar to Nintendo fans and even has a beam that shoots from it, although Link tends not to decapitate quite as many people as this game does.
Katana Zero is a brutal game, with blood splashing freely over every surface. It has stealth sections and seamless action. Conversations have an actual impact on your game and you'll want to discover what's at the root of your nightmares. War may be hell, but hitting a bullet mid-air with a sword in slow motion is tremendous fun.