I tried doing screenshake for an older rail shooter of mine. The results were... nauseating lol. I might just do a spark effect or something to complement the red border, especially since I already have the camera moving with the gun. But you're right that more hit-feedback is definitely needed.
Sorry you found the crosshairs confusing. Was it just a matter of having the second smaller crosshair, or was there a more fundamental issue with aiming (something I've struggled with in past rail shooters)? I pretty much ripped it straight out of took inspiration from starfox64 when making the crosshairs, and that game uses 2 without issue, so I (wrongfully I guess) didn't expect it to be an issue here.
Thanks for playing, and also for the feedback!