I'm having difficulties getting the fun factor into this iPhone game, and I am looking for some ideas or advice. I was asked to generalize the question a bit.

What are some techniques for arcade highscore games that can be applied to this game in order to:

• Make each second of the game fun and challenging, from the first second to the end of the game. Regardless of skill level.
• Make the player want to try again and again to beat the high score.

Briefly about the game: you aim using your finger and pull the bow chord and release by lifting your finger. That part feels quite nice how the bow interacts with the finger.

The game idea: hearts fall down and you get 1 pt for each heart you shoot. You start with a few arrows and every now and then a bag of arrow comes down which - if you hit it, you get more arrows. Once your out of arrows the game is over. So it is all about beating your previous high score or your friends high scores.

Unfortunately I don't find it that fun. Thankful for any ideas/suggestions/thoughts on how to make it more fun/interesting.