An interesting way to spend time, but the ads are oppressive. You spend more time watching ads than playing the game. You do get an opportunity to get free upgrades out of the ads but that just makes you feel like you have to watch them or waste time. Maybe the ads could be marginally acceptable if the game generated currency during the ads but it does not. You are ground to a complete halt. These are all 30 second ads with that short time before you can quit them after too.