To beat the dragon make sure to buy as many tiles as possible on lvl 15. It will take awhile and your heroes will walk everywhere but the dragon it seems, but they spend all that time healing!
deep strategy is a lie. pretty much use fire for the majority of it and only upgrade general skill. i get problems with sounds playing delayed and also sometimes can't click my units during a wave sometimes. needs more enemy variety. anytime fire resistant guys do show up it doesnt matter because my fire units are powerful anyways by that time. only three of the levels were different from the rest: the total flying one, the rat one and the one requiring only blue units to win. interesting at the start but becomes slow and repetitive later.
 "Dungeon Developer"){kind=icon}
 "Minions"){kind=icon}
 "- Music in Motion -"){kind=icon}
 "Platform Racing"){kind=icon}
 "ZunderFury"){kind=icon}
 "Protector"){kind=icon}
 "Zwingo"){kind=icon}
 "Treasure of Cutlass Reef"){kind=icon}