Koei's Fatal Inertia has had a rough history: It started out as a PS3 exclusive, missed launch, became a default Xbox 360 exclusive and now is now being ported to the PS3 as Fatal Inertia EX as a PSN title. Ouch. Looking back at how things have panned out, lead designer Mike Bond says:

Yeah, the 360 demo didn't run well and we really regret releasing it when we did... The final game performed substantially better but still often dropped frames... In FI EX, we've dramatically improved the frame-rate again and I think players will be pleasantly surprised... This combined with a significantly higher game speed makes for a much, much nicer experience.