5 stars: I have downloaded this game on multiple devices, best of its type. The levels/bosses are really cool and unique. Very few adds, not pay to win and really fun, only problem is it gets a little grinding but the game makes the levels harder with higher reward to make it interesting. My tip is to not upgrade health because to you have to anyways, it is very risky though.
4 stars: Pros: Excellent Graphics. Good Control. Good game progress system. Developer is not greedy :D Cons: Levels after 10 are extremely difficult and game progress almost stalled there (at least for me although I'm playing this game from last 7 years and still stuck at level 11).
4 stars: Thank you for the awesome game, however I faced an issue, my purchases and achievements are there, but my progress has disappeared, as if it's my first time installing the game, I tried reconnecting the game with Google play services but when I access the settings again I see the service is disconnected.
3 stars: Shield, laser, and bomb are BS micro transaction bait. I was ready to complement them for how finely tuned the costs for upgrades and upgrade accelerations was, but those 3 upgrades are only good for whales. The first couple levels are a great time, but your progression will eventually get extermely slow and boring. It seems like in so many places right as I think they're doing something right, they turn around and slap me in the face.
3 stars: I'm really enjoying the game. It's quite fun and...