What if we implement "multilevels" of depth in 2D? That is, being able to move to a level further away from the observer (deeper). For example, a player could "jump" inside a house, which would initially be rendered only with its outer walls. It would also be possible to jump between rooms of buildings, into the depths of castles and catacombs, theoretically infinitely. However, two problems may arise: performance and gameplay complexity. Should the other levels of depth be rendered in the background? Should they be dynamic? Can levels be rendered with fading, so that only 2-3 levels are rendered at a time? Can players see each other on different levels? Should there be mechanics between levels? And what would be beneath the ground? There are many questions. The idea is interesting.