Although Mario & Wario was released only in Japan, the game is entirely in English; a US release was planned, complete with box art, yet never materialized.

Of note is that the scrapped English box art features a logo identical to the one seen on the title screen, and that the game itself contains unused graphics for a Japanese version of the title screen with a logo identical to that seen on the Japanese box art. Combining this with the fact that Nintendo games' title logos rarely deviate from the box art (and vice-versa), this implies that the final game is actually based on an English prototype which was shipped to Japanese retailers by mistake.