Exodus 20:3 (King James Bible) thou shalt have no other Gods before me
The Mosiah 12 version of the first part of the Ten Commandments has one significant difference in the first commandment: namely, the singular God versus the plural Gods. It is, of course, possible that the singular God in the Book of Mormon text is due to scribal error (𝓞 is not extant here). On the other hand, the singular will work. Note, in particular, that the biblical text has two passages where the singular God is used when referring to the first commandment (the singular occurs not only in the King James translation but also in the respective Hebrew and Greek originals):
The critical text will therefore accept the singular God in Mosiah 12:35.
Summary: Maintain the singular God in Mosiah 12:35, even though the corresponding text in Exodus 20:3 has the plural Gods; the singular God could be the result of an early error in the transmission of the Book of Mormon text, but usage elsewhere in the biblical text supports the singular as well as the plural usage.