If you wanted to show everyone this fake you (possibly) made, you left so many bad things in it, it is easy to tell it is fake.
1. The Wi-Fi symbol should be on the top left corner, not bottom left.
2. They would not name it Pokemon Arceus, luckily (possibly) you spelled Arceus right in Japanese.
3. They would not use an old picture of Arceus, on the box art.
4. The Nintendo Logo and The Pokemon Company Logo should be smaller in the bottom right.
5. You forgot the ESRB rating, even if it was not rated, it would say RP.
6. You forgot the "Online Interactions Not Rated by the ESRB".
7. The Cartridge ID does not have to be on the box, which you located in the bottom right.
That is all I can find that is total fake minus the fact it will NEVER come out. For an Arceus fan, try doing more research on box art before making a fake.