For those who are struggling with the zombie hydra boss: Standard boss rules apply. That is, buff everybody's defense and Matt's attack and debuff the boss. Then use Holy Sword attack and Judgement attack on the boss till all of them are near death. Then on the next turn, kill all of them. Make sure you leave none at the end of the round. Debuffing their evade is also a good move.
I don't know if this has been reported before, but here it is: After a few minutes of playing the sound of starting a battle(the one that sounds like an explosion) starts looping itself and never ends, even in the main menu. Hope this is fixed.
I found a bug(kind of). If you had enough magic pickaxes, you could easily bypass the Spider(and other bosses, I haven't tried) without fighting it and you can get all the rewards without fighting it.
 "Legend of the Void"){kind=icon}
 "Epic Battle Fantasy 4"){kind=icon}
 "Raze"){kind=icon}
 "Billy the Pilot"){kind=icon}
 "The Money Makers"){kind=icon}
 "Shop Empire 3"){kind=icon}
 "The Enchanted Cave 2"){kind=icon}
 "Bloons TD 5"){kind=icon}
Try again now... If still not working plz give us some more details...