I just played the demo. Personally, puzzle games have never been my thing but I still thought what you made was pretty clever. A few things I wanted to point out.
First, on the main menu, I actually had a difficult time trying to start a new game. I tried clicking on New Game and nothing happened. Eventually I figured out that spacebar did the trick but unsure if that was intended or not.
Second, I think there should be an option to rotate the camera. Specifically, on level four there was an instance a couple times when I was trying to determine my steps but I couldn't see the number pickup that was behind my block. I think the ability to rotate the camera or have some type of transparency on the character when its blocking a pickup would help with that.
Finally, I think having and indicator to show the block's facing might be a good idea. What I mean is some sort of arrow pointing where straight forward would be. On the last level specifically, I kept going the wrong way or falling off because for some reason I kept thinking backwards meant coming towards the screen when in actuality I needed to go right. I think it may have been because the angle of that level had been a bit different from the other levels and because it was a lot larger.
But good work! Seems like you have something solid here.