Which Pokemon game claiming to be X-Y is this really?
There's a Pokemon game claiming to be Pokemon X-Y hosted https://www.playretrogames.com/1111-pokemon-x-y .
I don't think it's Pokemon XY, it seems closer to Alpha Sapphire. It has locations such as Petalburg City and Rustboro City.
Which game is this, actually?
Judging the years on the first screen, that's a hacked version of Pokemon Emerald.
You can see the same intro in this video: