Nice, a good old shooter with upgrades!
Would be nice to have a way to pause. And some way to turn off menu music but still have in-game music so that you can leave it open when doing something else (or just have pause mute the music once there is pause)
Showing total money in the game over screen would be nice so you know whether to press Try Again, or go to the shop in the level select menu
One question: given that this game is written in flash, how comes that this one works with ruffle on newgrounds, but older newgrounds flash games do not work that way (say, e.g., bullet heaven 1)? (supposedly there is a newgrounds player but not for the platform I use)
EDIT: would also be neat if hard mode would have an extra tier of upgrades!