Cubically, 4 bytes, score 0 4/ NaN∞

B3%0

Works in every version your system has enough memory to run. Non-competing because it's lame. Valid per this meta post.

Basically, B3 rotates one row from the left face into the top face. F3 would work just as well, as would F₁3 or B₁3. As one row in Cubically 3x3x3 is three cubelets by one cubelet, this puts three 1's into the top face, giving it a face sum of 3. %0 prints that top face sum, printing 3 for Cubically 3x3x3.

In Cubically 4x4x4, rows are 4x1 cubies. Puts 4 1's into the top face, yielding a sum of 4.