I've got some "Pac Attack" food pellets. So far, only my cat has shown interest in this food.

I've tried rubbing his lips with the pellet of food. For twenty minutes. He'll either wipe it away with his foot or move away entirely. This is the primary suggestion and i've tried it, maybe six times in all. Six twenty minute frustration sessions. I'm afraid I may be teaching him to hate the food this way.
Tried pretending like it's a cricket approaching. No response. We know what crickets look like.

Frog is apparently way, way too smart for that kind of stuff.

So, i've stopped feeding entirely for a few days to see if a hungry frog helps at all.
Maybe hunger will help.

What other things might I do to try and get him to show interest in a food pellet?

Seems like the frog is insists that his food be alive and moving.