What temperature and humidity level do you keep him in? Those are important factors that affect a pacman's appetite. Temps should be 85 deg F and humidity around 80 percent. Definitely keep the frog on a cocofiber (those expandable bricks) substrate, as other types of substrate can cause impaction.

The substrate should be moist at all times. Just pour some dechlorinated water in there so it'll be damp. It's a bad idea to have crickets in there with him at all times. Hungry crickets will harass and even chew on the animals they were mean to be fed to.