Nice little shooter! But where is the idle part? Is there a long-term goal that I just can't see?
If I lose the level it starts right back where I was. No chance of progressing in the long term.
The most upgrades are at the limit so it seems that the game ends with endless repetition at the moment.
But the start is really very nice and you can certainly make a nice "long-term" game out of it.
Keep it up!