It wa great, but needs some work...
Awesome, especially for your first game. However, there are manygames like this already on Newgrounds, so to make yurs stand out, you need some extra...OOMPH!
What i would suggest? A boss at the end of each level
Better explosions -flash made, instead of sprites
More levels!
More upgrades - they were good, but there could be more
More levels.... 8 wasn't enough!!
Hope to see more stuff like this from you, dreezn!