First of all: thank you for this nice comment!
The earth mobs are meant as an barrier for the "the ground is the limit" part. However it was planed to add a drop from the air mobs that cancels any earth attack. There was just not enought time to get it finished. (mostly because I tested in a flat world and wondert why it wouldn't work on normal terrain.... cave air -.-' )
Therefor it will be added when I have some more time.