Some design issues. One major bug (Or oversight?). The big one first: I just played to 42,225 points, at which point enemy waves stopped coming. Game does not end, I'm just flying through empty space. Am not sure yet if this consistently happens or was a bug, but in either case that needs to get fixed.
Some smaller points on your design: Giving the enemy missiles the same sprite as the player's was a bad decision. Makes it very difficult to identify threats. The smoke trails on friendly missiles also clutter the screen a lot and detract from situational awareness. Inconsistent telegraphing on enemy projectiles means some will blindside the player a lot - in some cases you have large, bright, flashing balls and in others use much less visible art that fades into the background with all the flashing lights onscreen. Consider touching those up to be more visible. It's unclear what several upgrade levels actually do - the second gun powerup, second mine, third shield, for example. More of a visual signature to confirm that the upgrade had an effect would be nice.
On the structure of your achievements, I personally really dislike objectives that prohibit use of a game's content, like the "survive X seconds/kill X enemies with no upgrades" ones. Those features were ostensibly put in the game for a reason, if you're going to punish players for using them you might as well not have.