I don't think I fully understand what the gameplay is. Initially I thought it was one of those sliding games like the pokemon ice gym, but I have seen that if I hit the keys in time I can change the direction, which makes the game much easier.
If it is one of those sliding games then you should put a check in the code that the player is not moving before reading the input so that the player cannot give any other inputs. But if it's meant for the player to move freely then I think you should put some kind of danger in the maze so that the challenge is more difficult.
In any case, if you wanted blocks to be aligned, next time I recommend you take advantage of the Unity snap to grid function, just hold down control so that the blocks are always aligned with the grid, you can change grid's size in the settings.