since my last review I've beaten the game, its was difficult. I will say paying for the upgrades wasn't worth it. because you'll never use all of them. the sniper laser and Canons work best against tanks as well as the time warp. Lvl 20 I cheated and looked on YouTube. I was fed up and wanted to get it over with. Over all I paid for no ads and leveled all the weapons for Nothing because after level 20 that's it. this game needs more attention. Kills need to be worth more as the levels progress..