If you have the Gold Edition or access to the specific DLC packs, you can bypass many requirements.

This is the "Holy Grail" for fans of the original game. To unlock the ability to play as the protagonist of the first Prototype , you must complete all sets of Radnet challenges. Once finished, you can toggle the Mercer skin in the "Rewards" section of the Radnet menu.

If you’re looking to maximize your style while hunting down Alex Mercer, here is the comprehensive guide to unlocking every skin in the game. 1. The Radnet Editions: The Primary Source

Once you have successfully unlocked a skin, you won't find the option in the standard "Pause" menu. To change your look:

This skin gives James Heller a more mutated, grotesque appearance, showing the true toll of the Mercer Virus. 2. Mutation and Evolution Skins

Note: Skins are purely cosmetic. Playing as Alex Mercer will not give you Mercer’s specific move set from the first game; you will still use Heller’s tendrils and powers. Quick Unlock Summary Table Method of Unlock Complete all Radnet Challenges Zombie Heller DLC / Pre-order Bonus Test Subject Heller Colossal Mayhem DLC Infested Heller Radnet Rewards Viral Infector Excessive Force DLC