Yes, you're right. The image size is fixed right now. This is one of the idiosyncrasies of the screen handling code originally made for fixed-size screens. As a workaround, you can try to use your browser's page scaling. I do realize this is a hassle. Sorry for that!
I will definitely improve this (though not for this submission). Thank you for putting up with it anyways!
Yeah, the auto-aiming is kind of a double-edged sword. Maybe there should be some grace period or something after it applies to allow for still changing the target manually? Not too sure.
Thank you very much for your feedback and for playing the game! Glad you had some fun!