The PS4-exclusive is set in New York during the year 2094, but players will also be travelling back in time.
"Ravens, a group of people who posses a special ability, are the key [group]," said Ono. "Other than being able to dive into the past, they are able to read the memories of objects and hear voices of the past. The Ravens in New York 2094 go to a certain time period, and use the information they scan there to try to clarify events of the past.
"As Ravens, players will proceed through dungeons in the past and investigate. There is a theme of ‘emotion’ in this game; there are various dungeons in the past that correspond to the feelings of human emotions. When you read a stone statue and enter a dungeon, things full of past thoughts and grudges are scattered around. If they touch those thoughts, they can read memories of the past.
"We’re calling Deep Down a memory reading RPG, but these words also sum up the objectives of the game: ‘emotion reading’ or ‘knowing the reality of the past. One of Deep Down‘s selling points are its self-generating dungeons, and how you’ll never enter the same dungeon twice.
"Well, I say ‘self-generating,’ but the system is not totally random. It’s a regulated random. It’s thanks to the ample memory and operating speed [of PlayStation 4] that this style of game is possible."
Visuals will also approach a level of photo-realism, according to Ono, as both weapons and armor will deteriorate and become dirty. Plus, due to the fact PS4's "operating speed is so fast," the rust and mold on players' equipment won't simply be rendered as textures; instead it will be calculated reflections the players interaction with the world, and one of the reasons behind the game being online only.
"Deep Down is an online game at its core, and as such an online environment is required, because PlayStation 4 is a new platform with an inseparable online component, we want you to expect an online system with as little resistance as possible," said Ono.
"We’re making Deep Down by aggregating the know-how of the ‘online’ segments we’ve cultivated so far. Even if you have only a small amount of time to play, we’re working hard to make sure to keep the tempo and enjoyability up. For those players who feel that online gaming is awkward, Deep Down can also be enjoyed by oneself.
"First, try playing solo, then when you become accustomed to it, try challenging dungeons together with other Ravens. We do want to lower barriers to play as much as possible. We’ve done as much as we can to create seamless gameplay, and the opportunity to shift naturally back and forth between both solo and multiplayer.
"Connecting to network is at the heart of the PlayStation 4′s hardware planning so making use of the online component has become very unconscious and easy to do. We will put management and continuation first. Because we want you to continue online play for a long time to come, we’re planning periodic version upgrades and large updates.
"We will continue to develop and manage at fixed intervals."
Ono went on to say that development on PS4 "was easy and precise, and that the things we wanted to do could be implemented relatively quickly."
"Even in the trailer released at the February press conference, we could see that coming up with something of quality was quick to do," he said. "For example, producing something at 60 frames and moving it in real time was relatively simple. That’s when I got it, that with just a little more time how much more we would be able to do.
"PlayStation 4 is about more than just satisfaction, it’s about feeling the possibilities. I’ve got to hand it to the PlayStation 4 folks for creating a system that’s so easy to work with."
The DualShock 4 will even have part to play as its light bar will reflect the game’s "theme of emotion with color." Players will be able to tell the color of the emotion of the dungeon they are in by looking at it and when Ravens hear "voices from the past," the sounds won't come from the TV speakers - but the controller's internal speakers.
Ono concluded by stating that the team is looking at using Vita as a way "to relax and play," and ways in which to use smartphones and tablets as well.
A beta will be released for the game "soon" after PS4's release, but just how "soon" Ono wouldn't say.