Free to play is obviously harder than the campaign if you pay but that’s how it is with games by this developer, the best of the best characters or towers and stuff are available for money. It is a bit infuriating at times but i understand it for the most part. Though my main complaint is that they took the same approach as they did in their tower defense game with the dark wizard as the main character and put some of the units behind pay walls. There should be, in my opinion, a level or two where you have free access to the pay wall heroes/units, so that you can play with the unit but have it not count toward any objective, kind of like a sandbox area. For instance, i want to use the dragon but i don’t know if i wanna buy it or not due to their play style, so I would try them in sandbox. Something like that would greatly benefit the developers if they continue with this type of approach, where the stronger towers/units and heroes are behind paywalls, but the free characters still have the ability to complete the campaign. Still a good game though