Okay, I tried your game! Here are some comments on it:
The graphics are simple but polished. The animations of blocks disappearing and flashing blocks help giving the polished feelings. The sound effects also support the graphical style well, so good job on that.
The gameplay itself isn't very interesting to me, though.
You categorize this as a puzzle game, but so far, I didn't find that many puzzle aspects (I played the first 4-5 levels). Instead, the goal in the levels is just to move from point A to point B. This is sometimes a bit frustrating to do, since you have to be very precise to make the block fit through passageways. Most of the time this requires you to be pixel-perfect. The fact that the controls aren't always as precise as you'd want them to be doesn't really help here.
You might want to consider making the game so that it doesn't require as much accuracy. I'm not totally against parts requiring accuracy though. After all, forcing the player to be precise bring challenge to the game, which I like. The accuracy requirement wouldn't also be as bad if you made the control system so that you can press two keys at once. For example, if there's a "T" section and I want to go down on it, I could hold down both "right" and "down" to make the character move right at first and then down when there's enough space to go down.
I also felt that many levels were kinda long in a sense. In many parts "nothing was happening", since you were just, well, moving with no hazards or anything nearby. You also had to back-track long distances in the levels. For example, the first level was very long, considering the only thing you have the player do is simply moving to different directions. I think even a much shorter level would be enough to teach the player the basics of movement.
On the other hand, 2nd level was nice because you actually got some action. The last part was a bit unfair because of the pixel-perfect precision it requires (which is hard to do with the current controls). I didn't like the fact that you had to go back to the beginning in this level though. To the player, it feels like you've beaten the level already, but then you have to go through all the obstacles you already cleared.