Got all of the achievements. Why these people are complaining on this game, it is not that hard and have a lot of strategies, also it is exciting. I was very satisfied when heard MoH:AA sounds (also DoD) :D
Science should be that interactive for kids. Great game, I learned something new. If you interested in such games I recommend you Socrates Jones Pro Philosopher on Kongregate
"Took me 2 days, hours upon hours of gameplay to get the hard badge. And it was totally worth it." It took me around 3 hours to win on hard difficulty (finally tuned deck! :D)
Conjuror should have some lifesteal items, All of guys should have some items on power regen(you shouldn't depend only from Conjuror mana restore). Warrior is welcome with lifesteal too and reflection (I bought some Quickness items too)
My ranger was with venomous bow and some quickness items too.
Cleric always should have accesories "Censer" (+50 to all healing abilities), btw his quickness was the lowest in my party.
I hope you can win 40 waves with some of my advices. Good luck
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