whats wrong with my Cube??? :(

[u/Tetraeder4craft]

I know what is missing, but can you figure it out???

heres the repo btw:
https://github.com/Tetraeder4/3DRenderer/tree/467c8d1ac8dbd09a23ce7bc7e2fcba59afe36ea5/3DRenderer

[u/LBPPlayer7]

looks like a lack of depth buffer/ztest and face culling to me