Left/Right controls only seemed to work 10% of the time making it extremely difficult to figure out the game.

The game is great!
I've played and finished it. At times, pixel feels irresponsive. Aesthetics of the game is wonderful, but only for the playtime I spent(meaning - if you are going to add more levels, change the background day/night cycle for something else)
 

The game was pretty fun and quite challenging. Seems like I can jump up through the obstacles - is that intended?
A bit weird feeling to control - perhaps just needs more practice.

I like the simplistic style and the changing background color all the way to pitch black. The controls are not quite working yet, though and it might get a bit boring - the game play as well as the design.

The music sounded very familiar to me: I have the same Garage Band loops in a song of the game that I have submitted here ("The Last Secret", my song is called "Secret Stars").  I was very amused that we seem to have the same taste... :D

Feedback Notes:
- Concept is nice. Pixel platforming feels like it could open the door to very very technical and precise gameplay.

- Controls felt pretty wacky and unpredictable. They did not always seem to work. I think something about the input handler must not be integrated correctly.

- Screen going all black is not very nice.

- Could use some sound effects, at least for the jump and landing.

- Interesting demo. This could be cool with more development effort.

overall fun: Fresh concept, I like it. Sometimes it seems the cube we control glides more than other times. Also some ranges of blocks we can go over, I expected to be blocked by those when jumping from below them.

UI: Simple and clean

Art: That's a cool concept. Maybe there could be some sort of art of pixel art instead of the gradient background? Ways to innovate.

Sound/music: A bit "placeholderish"