O yeah, we can call it a "clone megamix"!!
Maybe Gradiente and TecToy shared plastic molds to cut costs?
Tokumaro is correct about the
button's functions.

I saw some blog posts teaching
how to swap the A and B buttons, so they become a little more like the real thing.
Some people even say that it's even better than the real thing because it has no jailbars.
I think the guy is looking at it with "pink glasses", since it has jailbars, and very noticeable!!
The only advantages is that it can run bootleg games without moding, and didn't need transcodification to show the image in colors on Brazil back in the day. Maybe the cartridge connector was better, but I have some doubts about it.
I recently have fixed one of these on
this thread and looks like Zepper is trying to fix one
here too. I really hope he succeeded!!
It was told that Gradiente had an contract with Atari, and sold the old VCS here with the brand Polyvox.
They were intending to release the 7800 too, but since it has not a stunning succes as the NES, they decided to use the already made molds and clone a NES instead.
I also remember calling the CCE controllers the "Batman controllers".
Sometime later the console was shipped with a Batman cartridge with it.
AFAIK all these "heavyweight" manufacturers release their clones because of the market reserve politics, that basically forbid importings and such.