Suda51 has explained the mechanics behind Let It Die, developed from the Lily Bergamo demo.
The theme of Let it Die is survival action. We see the player kill enemies and on the flip side, you’re just trying to survive. When you think about the title, another way of looking at it is you’re trying to live. In the trailer there is a scene where a character grabs sand from the ground and throws it at the enemy. You can kind of see what players will do when they don’t have items or weapons in the beginning and they’re fighting to survive. The violence in this game is just a byproduct of trying to survive.
Most interesting is how the asynchronous gameplay comes in. When a player dies, their data goes up on the cloud, and comes reuploaded as enemy AI.
Suda51 didn’t explain how microtransactions will come in but indicated that it will not be pay to win. You can read more about it here.