Photo jumping was a really cool idea and I liked the monochromatic aspects, the sketch book artstyle reminded me of a noir detective novel or the Take on me music video. Unfortunately I seemed to get locked in one of the story sequences, but was able to experience the end of the game with the cheat code provided.
Viewing post in Detective Shade: The Turnabout Case jam comments
Your suppose to present clues to him and you need to get the info from Lucas to start suspecting and interrogate victor. At the end of the dialogue sequence, if you haven't fulfilled any of those, an inner monologue would give a hint on what you're suppose to do to proceed. If its the dialogue your softlocked at, try pressing enter. The bookshelf isn't meant to be interacted once you get all the clues.