I finally found the rating-button! I give this game 5/5 stars, because I like that:

• It has a demo!!
• It is rather small in size.
• Has lovely graphics, which aren't too complex or fancy 3Dish (perfect for mobile).
• It has a really great and addicting game cycle.
• The game mechanics are very easy to understand and still fun.
• The dev seems very responsive.

Thanks for this game and thanks for upcoming updates, if there will be some. I'd probably even pay again. (=