Quite simple but it's reasonably well executed for what it is. The difficulty progression isn't smooth, though, because the hunger meter speed doesn't scale with the availability of food. More speed doesn't make it more difficult because more speed = more food. Thus, in level 2 I feel like eating a spider means I'm in trouble. Level 3 and 4 are actually easier than level 2 and by level 7 or 8 I barely see the hunger meter dropping.