Tower of Thoughts

NOTE: The sound in the browser version doesn't work and I have no idea why.

My submission for Ludum Dare 49, with the theme of "Unstable".

A small creature wakes up in an ancient tower, its task to repair it, using it's own thoughts, creating rather unstable constructions.

Controls:
A, D - move left and right
Space - jump
Mouse - point at a letter, hold the left mouse button to carry it around, press the right mouse button to rotate it to its default state

There are 5 levels, your objective in each of them is to use letters to block holes in the tower (the letters turn gold when you successfully patch up a hole) and then make your way to the top. The third level may seem impossible, but it can be beaten, though it requires thinking outside the box.