Decent enough game concept once you turn off the ads with airplane mode. Though it does get a bit repetitive when there are only a few different enemy types and guns, especially since gun unlocks become more spread out the further in you get. Honestly in this state not even worth the $2 remove ads purchase some other games of this type have when it's just a concept, the very basic level of coding to make something look kind of like that concept, and an ad script.