Instead of releasing Ketsui themselves, Cave licensed the game to 5pb. You may remember 5pb as the company behind Phantom Breaker or visual novels like Steins;Gate. Ketsui is one of their few shooters with Xbox 360 exclusive Bullet Soul being another.
Ketsui: Severing the Bonds of Hell Extra is on its way to PS3. This version has the console-only X-mode and a port of the arcade game on one disc. The limited edition package includes a Superplay video on Blu-ray. Ketsui will be available on July 25 in Japan.