for little forest place 1 warrior second tile in near the entrance. Upgrade to physical asap then give it consecrate. Build it physical all the way except after wave 5. Give it special once to get consecrate to 150%. Then go back to damage again. Place a few buffers towards the back to mop up fast units and you can get the warrior to max level and win easily with no lives lost
The Exp system adds strategy to the game, it prevents you from say using an archer to to take out some flying waves then creating a damage heavy strategist to deal with a boss.
The placement of archers right away would again remove a strategic element and damage based mages would become obsolete due to the warriors damage bonus.
The fact that you can't sell units means you have to place them efficiently, even more so when paving a new tile.
Beserk seems fine to me although I will agree criticals can more often than not seem very random.
The status effects to me encourage you to spread your defenses rather than piling in one kill zone while using mages.
The unit targetting can be frustrating but thats why you create a final buffer to mop up any stragglers that are missed or something to kill debuffed enemies quickly.
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 "Epic War 3"){kind=icon}
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