✓ Same family of puzzle-platformers: precision platforming, adventure storytelling and puzzle design
≠ Stands apart with strong narrative focus, dark, oppressive atmosphere and exploration and discovery, while skipping cozy, relaxing feel
Double Fine Productions and Tim Shafer are known for making very curious games out of amazing ideas. Psychonauts is exactly about some idea. You have to get inside people's mind and help them fight with their fears or memories from the past.
Where it drifts furthest from The Plucky Squire: tone and visuals.
It predates The Plucky Squire by 19 years, with what that implies technically.