GameEnd gallery save file is EndingSlot.sav wich can be opened with online save editos(just google ue save editor). File located in %localappdata%/Pasec1/Saved/SaveGames/EndingSlot.sav . If you dont have that file then loose twice to same enemy in game(example: worm). To unlock other gallery entities in gallery copy block in file and change its name to the name of enemy(example: "gallery_worm_0" change in copied block to "gallery_octopus_0" , it will unlock for said enemy). I guess omake save is Monsters.sav but save editors cant open that file for some reason