Wow. Is all I have to say about the look of the visuals. Now when speaking of gameplay, the visuals aren't great. At first I thought that the game was 3D or top down 2D, so I was drawing a large plane for the cube to navigate; not realising that I just needed to draw a line.
Since the lines of the cube are moving, it is hard to tell were the collider stops and starts (or is it dynamically changing with the movement of the lines?) This means that it possible to have white cubes with red just below it, resulting in the cube sometimes killing you and sometimes not.
I made it to the level with the large orange X. Though, the levels before that already made me want to stop, because of the issue outlined above. It is a nice touch that the main menu shows the current level, perhaps it can also give some visual hints to top it off.