Vertical open-world games possible?

I am very new to Unreal Engine, and was wondering if it would be possible to do an open world game, but focused more on vertical exploration. Think “Grow Home”, that Ubisoft game where you expand the big flower into the sky.

I know that horizontal open world games, like Fallout and Skyrim are possible, but from what I understand, that spawns and renders small sections of it at a time , limiting the memory used. If everything was vertical, would it still be able to only load sections of it? I would assume no, but just want to make sure.

Just to be clear, I’m not thinking nearly AS big as Fallout/Skyrim. Just would big heights be possible.

I’m pretty sure the SKY is/isnot? the limit! If it doesn’t work, try to break it into separate levels.

Yep, surely it is possible.