On your point of the game desperately calling for more interactivity, I think this may be the wrong way to go. UniqueGeese (who seems to be solely developing the gameplay from the credits) doesn't seem capable of delivering the sort of complex, original, and engaging gameplay systems that would match fans' expectations from the art team. If he were to simply strip back the YouTube jumscares he'd have a far more artistically successful, albeit much less marketable game. Imagine an atmospheric exploration of the ruined park, with an increasing attachment to Rambley mutually driving his selfish desire to keep you trapped inside to stave off loneliness.

These are just my thoughts. Enjoyed the detailed review!