This one was fun. The theme (odd rhyming couplets with Xs and Ks) (sooo many Xs and Ks!) was hard to guess at, but once one or two fell, the rest were quite easy. Still, they all made me smile.
Favorite clue: 22D: Where "K-I-S-S-I-N-G occurs, as taunting kids say" (INATREE). Least favorite: 9D: Keebler cracker brand (ZESTA). Never heard of it. And having entered "PREs" for 6A: Chief exec, we had to guess at that Z after we got the "There are incorrect squares in this puzzle" announcement.
Also enjoyed EARSHOT (20A: Hearing range), MITOSIS (25D: Cell division), and any mention of SKEE (31D: ____ - Ball (arcade game)).
A fair amount of AXER, IMAM, TSAR, and SSRS, but hey, it was ok.