The lava zone dialogue is a event trigger, I think I'll leave it since it's a very small bug with a less than straightforward solution.
The game is set in the same world of "That's my Exploit Keeper!" right after its events, since the "skill" to grow in size by opening the world map is a bug, story-wise. In the future I want to use more this concept of a world in the process of discovering the "exploits" after being freed from the developers, like the antagonist is doing (or the mother?), but it's something slightly more ambitious that I might consider in the future.
You can reach the snow temple before unlocking the Gemini Mansions, but it requires a harder solution.
Also, keep in mind the gemini ninja, she may make a cameo this April first... C: