There are to much cards to find alone, which is too difficult. (Redit: his has been fixed)
Plus there should be more entities (the wiki explain it), maybe like this:
—in dark and large zones there would be some Skinstealler, but mutilated (because they have been “operated” to study them in a hospital) and maybe some aggressive smiler
—at the start of the level, Scratcher should come from a logical place:
1-closed in a big caged because trapped by old scientists, and then get triggered and destroy the cage
2-he comes somehow from level 2 or 3 (if it is ok with the wiki, also if it has been invented by casual people)