I really enjoy the game.But after 50 hours of playing, your progress is down to 0. You need another 20hour so you finally collected materials and make some really small upgrades to items, heroes.. The cost of coins you needed to make upgrades are super high after some point. With this progress you can max out ONLY 1 hero after 2YEARS! of playing. So if you decide to pay some money Yes they will help you alot in the beginning. But if you play for a while your 20$ equal to only 5% total upgrades