Not bad, I enjoyed the game and got 95% everytime I played, I got 100% by chance once.
My only frustration is the text coordinates for the park was too small. Other than that, it was pretty much alright for me to proceed on. I do have much pleasure in completing the game, the clues was pretty straight forward. However, the door of the 3 spheres had me stuck,but through a little trial and error, I got through the door, and proceeded to play through as normal.
Overall, it was pretty much enjoyable, and if only the text for the coordinates was slightly bigger, I would have voted a 5.