Serious question - and not meant to be taken as a defense of Jpop or go off topic, but a sincere inquiry: At what point does an "homage" or "inspiration", even a subtle or subconscious one END, and "full credit originality" BEGIN?
The timing of this JPOP tangent is interesting, since last night while trolling the local Craigslist I saw a listing for a project '67 Jolly Roger. I'd never seen or heard of the game, so I took a look...
...and my first thought was "Holy Shit, that's like Firepower's father". I mean look at it: four top lanes with center target, surrounded by orbit shots, buoyed by a cluster of 4 pops, and a center "bonus" grid leading to the drain.
Give it a nip here and a tuck there to add some locks; populate the wasted space in the lower PF by slapping some targets in front of the pops, replace the right rebound rubber with a target bank, convert to an Italian bottom and boom: Firepower.
I always thought (along with most people, it seems) that FP was Steve Ritchie's original work. Obviously the flow revisions and rule set are to Steve's credit. But the basic playfield layout seems heavily inspired if not outright reworked from Jolly Rodger.
So at some point everything "original" is inspired by what preceded it. Being forthright, humble, and acknowledging prior work can get you some goodwill. But then the where do you draw the line for full credit?