First off, epic music choice - really pumps you up for battle! I can see the potential in this game, but it just needs a few more things to make it great. If you don't mind, I have a couple of suggestions:
First, there is no incentive to stop firing. Maybe you need some kind of resources that regenerate to fill your "fire bar", requiring the player to move around and collect them. Secondly, it gets impossible at around 60,000 points, but I'm sure you know that. A leveling up system, or some kind of tower defense style turrets for you to put up could give the player more power as the game gets harder.
The last idea is to have some kind of system for powering up the eggs. Maybe allow the player to take the eggs out of the nest, which would make them more vulnerable, but allow them to grow faster. Potentially, the more you allow an egg to grow, the more powerful of a dragon you regenerate as, or something like that. Glad to see you are carrying on with it - I'll definitely play it again once it's had some more work done :)