@Mark thanks a lot for the consideration and comments! Here are a few responses:
Eye candy does not make games better. Zombies, space ships, etc. are fun to make and pleasing to look at, but they do not make a game fun or playable. (My experience is with high school teens; I may be wrong when it comes to young children.) A good game has a balance of intellectual challenge, chance, and playability. This is the opposite of what most people believe about games. As you develop Bug Hunter, I recommend steering away from the artificial player-versus-bug analogy and just let the player demonstrate mastery.
This is just a prototype. What I was going for with the thing you call "eye candy" is a hint of storytelling. I mostly agree with your comment, but in a sense that good storytelling is not essential, but adds to the excitement. I think if wisely executed it could add to the desire to play more. A good example is http://codemancergame.com written by an avid WL user. Of course there is no story in a picture of a bug. But it is a placeholder for it ;-)
Humans love scores. If Im playing a game, I want to know whether I beat my previous score, bested my buddy, or even made it into the top ten on the leaderboard. In fact, that may be my primary reason to play. Perhaps thats coming for Bug Hunter. The one-and-done nature of the game right now seemed lacking.
Yes, gamification is the true essence of these things. It should be in the game. I said that at the end among improvement points: "Flexible scoring system based on function usage frequencies."
3 & 4
Yes, agree absolutely, thanks for the feedback!