Testing again :
I am very sorry to say it, its unplayable. Was testing 5 different versions and I get the save file error on all versions, in main game and mission pack.
German ISO compiled myself - save file error ''Prespawn not valid'' - chapter 2
US ISO compiled myself - save file error ''Prespawn not valid'' - chapter 2
GOG version compiled myself - save file error ''Prespawn not valid'' - chapter 2
p2p youtube compiled pack - save file error ''Prespawn not valid'' - chapter 2
p2p medifire compiled pack - save file error ''Prespawn not valid'' - chapter 2
Testing all the time Crusader with rocket weapon on easy difficulty. Chapter 2 and 3 has texture glitches that also break up the game and playing single segment is also not working. Rocket weapon also give texture glitches and break up the game.
Music was active all the time, not tested without music.
Final verdict :
I am thankfull, but not playable. Its the only PC port for the Vita that make so many trouble. Has anyone done this port from start to end ?