Wow, that looks cool. Portals are a great idea and seem like the would be (relatively) easy to implement in a raycaster!
The simplicity of them makes them fun to experiment with: I used one in a Ludum Dare game (https://www.mrspeaker.net/dev/ld27/) and made the field-of-view and movement speed a "mechanic".
The simplicity of them makes them fun to experiment with: I used one in a Ludum Dare game (https://www.mrspeaker.net/dev/ld27/) and made the field-of-view and movement speed a "mechanic".