1. Unlike the board game, this version has unfortunately only one extension. This gives nen quarter star deduction =)
2. When you play with many computer opponents but you have to wait very long until you're back at the series. I hardly think that the software takes as long to calculate the next step. Unfortunately, you can not adjust the delay, and in evaluating it takes forever until you see the result - again a quarter of a star deduction!
3. Eats the battery. I have rarely had a game that requires as much energy as this. A game with three opponents calls from my Galaxy S3 10% battery! Since the last half star is still potential for improvement, thus gone.
Otherwise, highly recommended!