Yes. I should have added an additional statement that these games actually promote themselves as clones.

UberBlox

"Im making a kinda of Minecraft Clone"

https://www.allegro.cc/forums/thread/605337

Manic Digger

"an open source clone of minecraft"

https://github.com/henon/manic_digger

I made a mistake with FortressCraft. After reading the Wiki apparently there was a dispute between themselves and Minecraft.