YAPP: Yet Another Puzzle Platformer

You wake up in a strange place, find yourself turned into a solid-colored sprite, surrounded by barriers, buttons and gates.
You enter a gate, a new world with seven puzzles and a castle is shown.
All you could do is to solve the puzzles.
In this game, you have two abilities: cast a shadow at your position and teleport to your shadow.
Unlike most puzzle games, nearly no new mechanisms are introduced after World 1.
Instead, new usages of your abilities are introduced throughout the whole game:
Simply cast a shadow to hold a button.
Use yourself to hold a button, with your shadow waiting at the barrier, teleport and run through the barrier after it is fully opened.
Attract the guardian with your body and teleport back to break in.
"Throw" your shadow by jump and cast, followed by another jump and teleport to "double-jump".
You can't touch your shadow, but you can put a box on your shadow, then jump onto the box to get higher.
And more.
Use your creativity, go through the obstacle, find the secrets, and figure out what's inside the castle.

Features

• 6 worlds, each has a different theme.
  
• 42 unique puzzles, including some challenging ones.
  
• Puzzles can be solved in any order. (feel free to try another one when you got stuck)
  
• 10 stars.
  
• Changable timescale. (which reduces wait time and helps a lot on the platformer part)
  
• Notice boards everywhere.
  
• And a philosopher.