Sometime in 2016/7, an anonymous user on 4chan apparently worked on porting Hydra Castle Labyrinth to the Nintendo 3DS. Then, in March 2017, a GBATemp found this user’s work and brought it some visibility. Shortly after, the 3DS’ port source code was uploaded to GitHub and it turned out that it contained a nearly complete PSP port! Hydra Castle Labyrinth for the PSP works quite well and it’s on-par with the PSVita port!
Fast forwarding a little under a year, in February 2018, Wololo /talk user “carstene1ns”, with the help “ptitSeb”, was able to polish up and fix up the PSP port enough so that it could enjoy by the public. I personally tested it on my PSVita via Adrenaline and these are my observations:
Sound and music work
Performance is quite good and I didn’t notice any stutters in my short play session
Both the d-pad and the analogue stick can be used for movement
There’s an option to use 1:1 scaling, to fill the screen while keeping the game’s aspect ratio (4:3) and to stretch the game to 16:9
There’s a blur mode which you can enable for smoother graphics