"The Last Experiment" is a base-defense strategy game. Your base starts as a small shelter, and your mission is to conquer a devastated, monster-infested Earth set in the year 2805. You’ll attempt this by planting radiation-resistant crops while deploying unique combinations of passive-defense tools—designed by the player—to fend off the encroaching "Fleshvine." Your goal is to prevent it from breaching your territory, killing your creatures, and infiltrating the remnants of humanity at your base.