Rusty-sword jumps in the demo
The developer explained that rusty-sword jumping could take demo players into areas not intended to be open. Those areas may be broken, unloaded or unfinished.
Reaching a place by jumping across a gap is therefore not enough to show that it belongs to the normal demo route. If the environment stops loading or a route seems unfinished, consider the intended demo boundary before treating it as a missing quest step.
What Holy Sword Endu is meant to do
The full game’s description presents Legendary Holy Sword Endu as a way to fly between platforms. Its upgrades are described as extending flight distance.
That announced traversal system and the demo’s unintended rusty-sword movement should be kept separate. A video showing a sword jump does not, on its own, establish a normal Endu pickup or upgrade route in the demo.
Stay on a useful route
For deliberate demo goals, use the achievement conditions, hidden meal route or Demo 1.0.2 shop steps. These pages describe specific destinations and prerequisites rather than out-of-bounds exploration.