Hmm...a cross between Ikaruga's polarity, Psyvariar's grazing, and Night Raid's positive-negative gauge, of all things.
Anyways, this definitely sounds interesting, I'd love to try out a demo to see it in action. As you say, everything will have to be placed very carefully to create good scoring opportunities and such (especially if acquiring bombs and whatnot depends on how well you can score), though the fact that you can draw shots to you from anywhere onscreen (as opposed to only being able to, say, fire straight forward to chain in Ikaruga) might give you a bit more flexibility. Definitely see where this concept takes you, and if something seems off you can always tweak it. Nice idea!
