Over at shmupemall.com they were able to interview mr. Horii from the company M2 ShotTriggers during the 2018 Shmupfest in France.
He talks about their Ketsui port to the PS4 and also on their new -kind of strange- Mononoke Ninpo-chou game (more info on this game you can find here).
Go have a read over at http://shmupemall.com here (original French shmupemall.com here) it is worth your time!
Left Noaki Horii with Yosuke Okunari on the right