The game viewport is pretty small and does not offer an option to fullscreen. I had to use the browser's zoom to play it. The instruction text at the top is hard to read. It needs a contrasting background, or to be a different color that helps it stand out from the current background.
The instructions don't mention that you can use WASD to adjust the camera. I would add some instructions to the game page mentioning basic gameplay and controls. It would also be nice if there was a button to reset the camera, as the controls are not the most pleasant to use. It is good that the camera resets when the level does, but I'd like to just reset the camera. Even being able to move the camera, it does not give you a good view of the whole course, which prevents you from really being able to plan out how to get through it, yet it feels like you need to plan ahead and move over several steps in a single action, especially using the momentum from your first push to chain into the next moves. I did manage to beat the first level after several tries, though I'd say part of it was luck.
The UI really hurts the fun factor. The puzzle mechanic looks decent, if you could just see it better. For the first level it would probably be more fun if the view was simply top down, possibly slightly at an angle. I don't know what other levels are like and if the camera will be more important there. Perhaps the camera angle was meant to add to the challenge, but if so, it does more to hurt the fun than simply add challenge, at least for me.