It's pretty fun, but it does have its problems. Number one is one that has been mentioned in several other reviews: the difficulty curve. I've noticed the XP you get doesn't match to the total you can earn. As you level up in a game, the monsters drop more XP as you need more, but this game doesn't seem to do that. Not even for the hard levels. Problem two is that you need to clear an OBSCENE amount of sky tower levels to unlock more campaign levels.

it's okay but it's just like every other game like this. Your player only shoots when you're standing still. So you got a million enemies shooting at you and you have to move constantly. Then when their bullets hit you it only takes like two shots to kill you. so of course it's like every other phone game pay to play. and the one thing that I don't get is you can only get hit five times to achieve the star. if you have the shield it blocks it doesn't give you damaged but still counts as a hit??

Purposely searched "offline games". As you may have gathered, this game requires an online connection at all times. This is either a deficiency on the Google Play store (shocker) or the developer (another shocker). Either way, this game is not for those who travel and don't always have a reliable network connection. Unfortunate, as the game is a lot of fun.