5 stars: No ads. It's very simple, but an awesome game. You can change the size of the game square. It keeps records of time or move counts. Honestly it's simple, but it's great.
5 stars: Amazing app! Love all the options and stats. One suggestion for a future update: I wish the move counter counted taps instead of tiles moved. If you tap several tiles away from a black tile to move several at once, it ups the move counter by however many tiles moved. This also throws off TPS (turns per second) in my mind because I think of that more as clicks/taps per second, not purely tiles moved.
4 stars: can't get out of easy mode
2 stars: Not for fast players, you need to wait for animations when playing, and even if you disable animations some taps don't register because your finger slid a little while tapping, useful stats though.
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