First of all, apologies for the terrible quality but nico nico sucks basically. Hopefully Koei post the direct feed gameplay for this.
In the meantime please check out the gameplay below-
https://www.youtube.com/watch?v=yuY6R-iF3XU
Here is what Brenna Hillier from VG24/7 had to say- http://www.vg247.com/2015/09/17/holy-shit-team-ninja-has-basically-made-a-dark-souls-game/
The game is officially described as - Dark Sengoku Action RPG and is developed by Team Ninja with the publisher as Koei Tecmo Games. The game will be launching worldwide exclusively on PS4 in 2016. And yes, it's 60FPS.
Please see the official HD trailer here - https://www.youtube.com/watch?v=IvfGYXIOems
This was the first time I've ever heard of the title, but the gameplay and atmosphere had me hooked immediately. Can't wait to play it. In the meantime, though, I decided to translate some of the information given in the video in the OP. Some of it is explained in the VG247 article, but not everything. I'm far from an expert in Japanese (but I'll be going there for a year to study in a couple of weeks!), so please bear with me if there are some slight inaccuracies. I also couldn't make out the name of some mechanics.
- On the bottom right are four icons that determines fighting stance.
- Your Offensive and defensive capabilities are dependant on stance and can be changed on the fly.
- There are bloddy katanas on the ground where other people have died.
- Apparently you can active them and fight against them for good loot.
- (I can't make out what word they used to describe them so I'm not sure if you fight them in PvP or if you fight AI units that look like the players.)
- You can change armor and weapon in real time, so make sure you're in a safe area when you do.
- There are also spears in the game that are good against groups of enemies.
- There are guardian spirits that William can see and infuse into his weapon for a limited time like the flame wolf and the blue owl.
- Guardian spirits appear after you die. (I guess as a helping hand?)
- You will have to decide when to use it apparently, so there might be a limit.
- There are shrines where you level up with the experience you've saved up, and where you can change spirit.
- In some locations you might come across some strange flimmering (can't make out what they call it), which when you approach will spawn a youkai that drops good loot.
- The boss shown is called an onryou (revengeful demon), a powerful oni.
- You heal in realtime so it's important to look for an opening to do so.
- When he heals he infuses his weapon with what looks like a blue owl spirit, different from the fire wolf from earlier.