A back of the envelope calculation suggests that serving the game even on S3 would cost $2 per 1000 players - much less elsewhere (I use 100tb but that's overkill for you).
I don't know if you're keeping track of the conversions - from hit to download and hit to sale - but you should easily make $10 per 1000 hits. $3 is also too low; you're likely to make far more revenue at $5 or $7.
I wouldn't be surprised if this change alone raised your revenue by ten times or more for people not coming from the ultra curious HN crowd.
You also should make the intro more like 10 seconds long at most. Split the intro cutscene up and show it slowly over the levels.
Seriously. You need to do this. I guarantee you're losing at least half the players.
Some other notes from a quick playthrough:
* Shadowing is impressive!
* You should probably scale 2x by default. Full screen is too big and default is too small
* I love the premise of the story
* You should have a visual reaction when you're hit
* Sticking in the same direction as you're firing works but I would limit it to key down, not key hit - let the player turn as normal when they tap fire
* It would be awesome if stalactites fell when you shot them, able to take out enemies
* Unfortunately I closed the game accidentally having gotten this far in the list and couldn't bring myself to button mash through the intro again :)
One last thing; I understand that it's the end of a long project and you just want to get it out. But the hours you spend to get the launch right (marketing, testing, feedback from friends etc) are critically important to the success of the product as a whole.
They're easily worth 10x as much to the bottom line as the hours you spend hacking away in the middle of the project. Single changes can have a 20% or 50% or 100% impact on sales.
I wouldn't try to release quickly and barely test a project I've been working on for two weeks, let alone two years - something to keep in mind so you don't have to learn it the hard way like I (and many others here) did.
In any case, great first project! Do you have a mailing list to sign up to? I'd be interested in hearing about whatever you come up with next.