This game is great, albeit too easy to be considered any sort of challenge (for reasons mentioned by previous commenters). I think it's an excellent introduction to defense games for inexperienced players. Allow for more than one saved game at a time and add some harder challenges of the type "finish the game without ever losing", "finish the game without replaying any previous days" etc. and your game will be perfect. 4 stars for now, definitely expecting a sequel :)
Small bug: Sometimes you click on a square on the grid, but it's as if you clicked on the one next to it. This happens when you click close to the border.
Notice that you can draw lines through the ball as well, so you can place lines just under it, lifting it little by little. That way you can "cheat" to reach high places.
This game is great! My only complaint is that it doesn't easily recognize closed shapes; they mostly come out as lines. Also, there should be a special way to make circles, it's too hard now. 5 stars anyway!
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