The game feels great! It's really satisfying to hit the bug aliens. It could just be I haven't figured out how to make other builds work, but it feels like Piercing Bullets + Extra Shot is by far the best way to get the kind of multi-kill power you need - the other area-damage type effects like Scorching Gaze, Thorns, and Shrapnel feel like they just don't pack enough punch to make up for it if you pick them over Piercing Bullets or Extra Shot. Again, it could just be my play style, but I think it'd be cool if there were more different directions to specialize in, so each playthrough felt more distinct based on which things you got offered. All that said, though, I'm really loving this game, I can't stop playing it!