The copyright in the title screen still identifies the company as Mojang AB, despite the name change

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Crafting doesn't work (at least properly)

No minecraft credits after end poem

Creepers use their hurt sounds as idle sounds

The first attempt to open a world fails badly

Zombie piglets (Baby Zombie pigmen) hold their sword incorrectly

Ghasts burn in lava

Wolves won't stop begging for bones after tamed and don't beg for meat even after being tamed. They also stay stood when first tamed.

The Wither uses spawn sound when dying

Trying to change skins to a custom one still shows alex on both sides

Tamed Wolves sit down when you give meat and the hearts are short lived as if it was newly tamed

When a Witch mumbles,there will be no subtitle showing

Throwing a splash potion of any kind will throw a splash water bottle instead

Wolves get untamed again when you leave the world and reenter

Endermen make stare sound even when provoked by attacking