It's been hotly requested, exploration of Lucis in Comrades. While this isn't a proper method of accessing the world, you can at least explore it and have a look at what changed.
NOTE: This has since been patched out as of patch 1.1.0!
NOTE: There are a lot of assumptions about Open World and what it should be. Please let it be made clear, this is an out of bounds guide, not content for the game that is hidden away. This is not something the developers intended.
The following objects and areas will freeze you or render the game unplayable until a reset:
* Royal Arms tombs & weapon collection
* Ladders
* Holes in the world (ie; unloaded dungeons)
Things I referenced in this video:
► Special thanks to HoboZone64 for this method, find their thread and a bunch of content discovered by them and the communiy on Reddit: https://www.reddit.com/r/FFXV/comments/7fiby7/the_adventures_in_comrades_open_world_and_how_to/