Ketsui: Kizuna Jigoku Tachi Extra was first seen in an issue of Famitsu two years ago when it was announced as an Xbox 360 title. What took so long? 5pb had serious problems with another Cave conversion, DoDonPachi Dai Ou Jou Black Label Extra. The game was buggy and used code from Arika’s PlayStation 2 port without permission.
At one time, Ketsui’s release was in question, but it appears 5pb hasn’t given up on the Xbox 360 version and it might even come out soon. According to Rakuten, Ketsui: Kizuna Jigoku Tachi Extra has leaderboards and shares replay data of the top ranked players.