What's the secret in the infinite purple room?

Solution 1:

Hint: Tilt your head the right.

Another hint:

The structure itself is a tetromino code. Decode and enter it for an anticube.

Answer:

Press → LT → A RT ↓ A ↑. An anticube will appear.

Solution 2:

Break it down:

The shapes of the platforms are joined Tetris shapes that signify a bunch of button presses.