Underflow studios invites you to throw custom sprites within this folder. Please be mindful of our supported image formats seen here: https://www.sfml-dev.org/documentation/2.5.0/classsf_1_1Image.php#a9e4f2aa8e36d0cabde5ed5a4ef80290b

Here is the list at the time of this writing (2018 07 07) (yyy mm dd) "The supported image formats are bmp, png, tga, jpg, gif, psd, hdr and pic. Some format options are not supported, like progressive jpeg. If this function fails, the image is left unchanged."