Takes place in the abandoned Playtime factory. Arrived here for an unknown reason, Jack must descend into the factory to seek out answers.
Your basic Poppy experience except the protagonist is a literal killer cyborg
This is the version of Jack right after he defeated the Keymaster and destroyed the Architect, which means he is fully developed and has access to all of his abilities. He also keeps the Memories he got in his own world, so is now very confused.
What can he even do? Well:
1 - Great agility: increased jump height, wallrunning.
2 - An easily accessible grappling hook built into his left hand, very useful
3 - Sensory boost: Temporarily, Jack can activate a function that allows him to achieve incredible speeds. This allows him to easily dodge attacks and counterattack.
4 - He also carries around a Katana. I think you don't need an explanation what that does.
5 - access to 2 of his abilities: Blink (an instant dash forward that dissects any enemies within the path), Tempest (A burst of air projected from his hand, non lethal.) Blink has a long cooldown, tempest has a faster one.
To compensate for Jack's power, most experiments have been buffed. They do need to pose at least some challenge to the Ghostrunner.
Half 2 - The Architect's angel.
Main character - Player
Takes place in the Dharma tower - last residence of human race after the earth was destroyed by the burst. Once prosperous, now led into chaos by it's new opressive leader - the Keymaster. Player awakes, driven by a voice in his head, and now must follow it's commands to survive.
Yet again, basically ghostrunner but instead of killer cyborg we have the player with his grabpack.
This player has access to every hand he ever had, and has been singificantly buffed to deal with new threats. And most enemies have been nerfed, and some rooms are now puzzle sequences instead of combat.