I love the concept, the art is really really could, but you absolutely need to ease the difficulty curve. I nearly stopped playing in the first level because I could barely go past the window (my bird would stop moving for seemingly no reason). When I finally got past it, I discovered levels that are way too hard x)
One addition that could help is to display a little arrow next to the bird to show the direction to the cursor.
That said, It might be the game I rated the highest, I really love it!