Games similar to TUNIC include Outer Wilds. It's paid, but Garn47 is free. Other options are Rain World. In total there are three Adventure Games like TUNIC for Windows.
An action-adventure video game that follows the player character as they explore a planetary system stuck in a 22-minute time loop that resets after the sun goes supernova and destroys the system.
United States
You are a nomadic slugcat, both predator and prey in a broken ecosystem. Grab your spear and brave the industrial wastes, hunting enough food to survive, but be wary— other, bigger creatures have the same plan... and slugcats look delicious.
United States
Garn47 is an adventure game where you explore to find secrets and meet new friends! made with Blender Game Engine
Mexico
