Click the flag. Arrow keys to move.
There are 16 subpixels in 1 pixel: 1 through 16. You can't see the subpixel. It's just a value for more precise positioning. Remember that the lines in the background are 30 pixels away from each other. When your press right, the block moves to the right 31 and 3/8 pixels or 31 pixels and 6 subpixels or 502 subpixels. The purpose of this is to have better movement and collision in games. Without subpixels, it's possible to move 1 pixel to the right but not possible to move 1 1/2 pixels to the right for example. At 62 x when you press right, the block moves to 94 x while when you press right at 0 x, the block goes to 31 x. It seems inconsistent but the block is always moving 31 and 3/8 pixels to the right. Without the grid, you wouldn't notice a thing.
