From the release:
Cactyys Totem Gaming, LLC released its 2.0 version of their Tb Top RPG Myythic: The Buried Temple of Alimar (The Game Without a DM/Gm).
The 2.0 core rules has new and updated spells, skills, and new reaction rules for the new player, while still fun and challenging enough for the experienced player. Full of more color, art, and in a new harder back version, 2.0 will be a delight.
To play, you use their online game simulator that has made major improvements over the version that launched. That will explain what the room is like that you’re in and other such details. So basically, the online system takes the place of the DM/GM for your game.
From there, it’s like a regular rpg. You’ve got your PHB with your character all statted out and so forth. Since the game doesn’t need a GM/DM, you can play solo or with groups up to 5.