A nice time-wasting game, great idea will be adding some more visuals for example: unlocking a new dragon, a new map etc... Add a D20 dice - very rare dice that AOE whole map, adding more enemies with different effects, and add a way to heal a dragon.
Make a rechargeable ability: roar - pushes enemies back one step. Make an ability to throw one more dice, make an ability to move one enemy... Abilities will appear at sufficient score and will need some points ore some time to recharge.
There is so much potential in this game and i like it!
--------- BUG REPORT!!!---------
Also a small bug in linux: right click breaks the sound. To recreate: launch a game in linux x64, right click anywhere - sound disappears.