The PSP port surprisingly dates back to '09. It was shelved in favor of the PS Vita version, but after the success of the PS4, PS Vita and MS-DOS retail releases, the dream of having the game on UMD suddenly seemed viable. I started finishing it up as a side project, but unfortunately, UMD production halted without warning and made that impossible.
Despite the news, I decided to release it anyway; digitally, for free to owners of the PS4, PS3 and PS Vita versions. Plus, UMD or not, it's still getting a special PSP retail display set, included with the first 3,000 copies of the new PS4 Retail Version! In addition to those, you can download the UMD disc label digitally, here, and see what could've been.
The PSP was one of the first platforms I worked on after entering the industry, and RCR
X's PSP version is my opportunity to give it a nice send off. The handheld will always hold a place in my heart, both as a gamer and as a developer.
With UMD production discontinued and the PS Store on PSP closed, Retro City Rampage: DX will likely mark the final PSP game ever released, but it can still be downloaded onto your PSP via your download list, or via USB using your PS3 or PC.