This is a revision of Moero TwinBee - Cinnamon Hakase wo Sukue!, likely addressing bugs or making minor adjustments to the original game's code.  The "(Rev 1)" designation indicates a first revision.  The specific changes implemented are generally undocumented, as these revisions are commonly for internal corrections or to improve compatibility.  The gameplay experience will likely be nearly identical to the original release, with any alterations being subtle improvements rather than major overhauls.

Moero TwinBee - Cinnamon Hakase wo Sukue! (Japan) (Rev 1)