WASD for movement

Left Click for shoot

R to reload

Enter to continue

Kill ash zombies that keep spawning

Corrupted Hearts reduce health but increase damage.

The health counts down to increase damage, there's a counter on the corrupted heart that is the pick up for the same. You can choose not to pick it up to keep your current health pool and it will count down to zero and vanish or choose to take it to reduce max health but increase your damage instead.