For anyone who struggles, here is the trick:
In order to lvl up VERY quickly max out your Haunted Cave skill (Undead Tree) and max out Infamy skill (Demons Tree). Then start any lvl and just press space and lose. You'll get around 50-70% of the maps experience due to miscalculations in the games formulas. That is especially usefull at late levels!!! + for others to see
ULTIMATE STRATEGY In order to win put a lot of archers for 50 gold all over the places and 1 guard for 10 gold in front of them. This will make an ultimate defence and even if some archers will die, you will have a lot of money to put them again.
i was sitting and thinking "game is soooo easy. why there is no auto fight option?" unless i took a boat across and found the SCREAMING PEPPER))))) ahahah