For people having a hard time getting started or getting past a certain level, here's what i did...
Start out with umbra, she's by far the strongest starting character. as you level her, put ALL of her stat points on luck only. Use your skill points on the master skill so you can have allies. Once you are able to control a few creatures, go to the "River King" (the first boss) level. Killing him multiple times for me yeilded many powerful charms and equips, this boss seems more prone to good drops early on in game. Once you've found a few +10 Defense/life/strength charms you should be good to cruise through the rest of the game, even those god forsaken Dough Nuts
I have a level 60 Umbra with pure luck stat and she's cutting through hard mode just fine. With the gear drops that she finds I was able to create an Atal tank that walked through the entire game in normal mode without taking any damage...
As for the game itself... Great game, great concept, but like many said before me riddled with bugs. My main character picked up one of the cursed "rune blades" and now cannot use one of my inventory slots. Many times I've had to save/quit because of invisible enemies at the end of a stage. 4/5 taking a star for bugs and a few game features that seemed redundant/useless. Big fan of this series and would love to see you expand on it even more!