The game is overall good. Like U$D10 (max) good.
The game offers lots of replayability, making you test and fail several times in order to get it right. Even with guides you will fail lots of times before getting it right.
So, if a game is so replayable why would I say its good and not great?
Well, the answer is that the game becomes frustrating REALLY quick. You get a note everytime you make a game, and many times you are punished without understanding why. The tutorials are good enough, but at certain point you are left alone to just discover by failing several times.
My out was to check a guide to understand more deeply what was going on, you might need them too. (there is a very nice wiki for the game so dont worry!).
Overall the game offers some nice gameplay with acceptable graphs and animations. Although its extremly basic-looking it has certain attactiveness.
I wouldnt pay more than U$D10, best price would be arround U$D5-7.