Fatal Experiment 2

v4.3.8·Updated 2025-10-19

The ''Deep End'' of GTFO Modded, are you ready? 25 Expeditions. Custom Guns. 150+ Enemy Variants. Team of 4 recommended.

About this mod Author’s original text

Welcome to Fatal Experiment 2 by Project Zaero.

Please report any issues you find to projectzaero on Discord.

The "Deep End" of GTFO Modding.

  • 10 Campaign Expeditions: Experience the storyline in Fatal Experiment 2.
  • Expeditions may last over an hour and will challenge your team.
  • 15 Bonus Expeditions: Arcadey / challenge levels.
  • Typically 10 to 40 minutes, these levels are to-the-point and get you straight into the action. They vary drastically and offer a wide variety of experiences.
  • 44 Custom Guns (6 are level specific).
  • Recommended to not use WeaponStatShower as it will hide information about custom weapon behavior.
  • Custom Melee Weapons: Sword, Sleeper Buster, Stick.
  • Heavily Modified Vanilla Melee Weapons.
  • Flashlight tool.
  • 10 Classes to pick from that evolve over the course of an expedition by earning XP from kills and assisted kills.
  • Many enemy variants with different abilities such as grappling, bleeding, knockback melee, and more, many with custom models and graphics. Because there are so many, here is a ridiculous spreadsheet with more info:

Credits

  • Dinorush: Weapon balancing and creation
  • コンボ/MaximumCombo: Japanese translations (disabled for new weapon descs)
  • KainKondraki: Chinese translations (disabled for new weapon descs)

Install & use Install: follow the bundled instructions

  1. Unzip the archive from playbuff and read the bundled readme / instructions first.
  2. Most mods rely on the game's mod loader — the usual route is a community mod manager (such as r2modman): pick this game, install, and it handles the loader and dependencies.
  3. For a manual install, put the mod files into the matching Mod / plugins folder inside the game directory.
  4. Launch the game to confirm it loaded; mods with listed dependencies need those installed as well.

Install locations vary a lot between mods — the bundled readme is the most reliable guide.

Dependencies

Install these first, or the mod will not work:

GTFOGiantGenerator-GlobalPunchdakkhuza-FloatingTextAPIFrog-GearPartCustomizationFrog-DoubleJumpLocalia-PingEverythingUntilted-FasterHackingMinigameFlowaria-LGTunerFody55-GTFO_ShootInTheAir

File & checksum

Filename
Fatal_Experiment_2-4.3.8.zip
File size
1.7 MiB