Entry Fee

An entry fee is required to play the Survival mode.
The required entry fee is as follows.

Stage Cores
X-1 5
X-2 10
X-3 30

If you can clear the stage, you will get more Cores than the entry fee.

Choosing Your Merc

Start the game by selecting one of the Mercs in your possession.
*Mercs at max Corruption cannot be deployed.

Mercs have a variety of abilities and weapons to fight the Infected. Most stats are handled the same between game modes, but the Stamina mechanic works differently depending on the game mode.

In Autoplay Mode, Stamina decreases over time.
In Survival Mode, Stamina decreases upon contact with the Infected.

Controlling Your Merc

Attacks are performed automatically, and you will be able to control your Merc with the WASD keys.

Upgrading Your Merc

Mercs get upgrades as you deploy them on missions to defeat the Infected in Survival Mode. Once the game is over, all upgrades will be reset the next you play. Weapons and upgrades change each time you play, so your game experience will be different each time.

Item Rerolls

When Mercs level up during Survival Mode, they can choose to acquire one of three randomly drawn items.
Players can reroll the three items drawn.
The first time during play is free of charge, but cores will be consumed from the second time onwards.
The number of cores consumed depends on the entry fee per stage.

Key Points

The stages that can be challenged change daily. Since the types of Infected that appear in each stage differ, having Mercs with skills effective against the appropriate type (e.g. humanoid killer, etc.) will give you an advantage in combat.

The choice of items that can be acquired when leveling up also has a great impact, so be sure to pick up the experience items that drop when you defeat enemies and aim for the strongest build.