I couldn't figure out today's theme based only on the first theme answer, SNACKATTACK, but I got the knack by the time I completed the third one, CRACKISWACK. BACKONTRACK, and the cool-looking YACKETYYACK complete the pack.
I solved the puzzle in the usual top-left-to-bottom-right order, and found I enjoyed it more as I went along. In looking over the puzzle for this review, I noticed that most of my favorite fill and clue/answer pairs were in the Downs - to wit: SARTRE, DRIP (Insipid one), BATIK, SABOTAGE, CHARMS, ROVERS, and CHAT. Coincidence? I don't think so.
I can't pinpoint the particulars, but this played a little slower for me than many a recent Monday. NADIR didn't leap to mind for "Very bottom" at 1A. It didn't help that I dunno who IDINA Menzel is. Nor did I know that PINETAR was a "Batter's grip-enhancing goo." Perhaps those lacks contributed to my slower PACE.
Not to give Mr. Mauer too much flack, but there was quite a stack of not-so-NEATO abbreviations through which to hack - ATA, AKA, MRI, NOS, and NES, and MRI - plus more tucked inside longer fill like ETCETC and SAIDOK. Also, if there are any AYE votes for 50A: "Muscles used in pull-ups, informally" (BIS) I'd be surprised. You can count me as ONENO on that front.