Its a time killer but very repetitive. Also you can earn a lot of coins and the only thing you can buy is a single gun about every 30 levels and you max out at 7 guns. Last but not least there are too many ads. There should be an ad maybe every 5 or 10 levels. It takes roughly 10 seconds to get though a level so when you finish so fast and there is a 5 second (when skipped) an it gets annoying.