Ads are rare and optional but devs really want you to spend money by popping micro transaction every rank up / mission failed / ect... it's tricky but you can actually have fun without spending money. Would rate more if there is other gamemodes, you just wait and try to find balance between ppl runing max assassins/ranged army, because they are so op. It feels like prisoner's dilemma , either you do it to rank up but get destroyed easily if they run assassins or encounter bad matchups 2/3 times.