Genius 153

[schweiss]

12A Games maker's new plan at Olympic opening (8).

Does it start with a Y?

[fiction-factory]

Just read the guidance
Fourteen solutions are derived from seven
common word pairs, each having a single letter
interchanged. Clues for these contain the
wordplay and letter count for the entry at that
number but the definition contained is for the
other derived pair member. Fourteen further
clues contain single superfluous words, which,
when correctly paired, give seven two-word
definitions of the original word pairs. The seven
remaining clues are normal.

May not be straightforward to solve then

[Neveracrossword]

Nintendo, game maker. N/new Intend/plan+O/Olympic.

The thematic stuff is rather complicated.