5 stars: The game is also gaming me, the game can decide when you can able to finished the chapter, the more I struggle to finish the boss level, the more I lose more gems, the game knows how to cheat... it can automatically adjust into hard planes and into one hit so it defeat you easily to lose more gems and to watch more ads or to purchase offers. But I'm still enjoying to play.
4 stars: Probably deserves a 3 star, but I'm still having 4 star fun and it's offline capable. Gameplay is fun and challenging, graphics are okay, multiplayer is subpart, upgrading planes is a real grind. Be prepared to watch five minutes of ads if you want any of the ten types of in-game currency. Watching a 5-30 second ad gives you 10 times what beating a level will award you.
4 stars: I need tutorial (help) separately. It is difficult for me to understand the game rule, especially regarding to the upgrade of airplanes, weapons types, and so on. In addition, this game forces users to play 3 stages sequentially immediately after install. This is a pain for players who have already played on another smart phone.
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