All the pictures from the CG gallery, saved via automated screen capture at 1080p in PNG format. From what I can tell that's the native resolution of the images so the capture should be lossless. A couple of non-H pictures at the end got cropped due to not fitting on screen.
Game site: https://ouo.io/qI5zdG Also on Steam in multiple languages: https://clk.sh/mJyDHvxk Game info: https://vndb.org/v26344
Content warning: blood and gore [gore filter available in game]