(Edit: in regards to another review here regarding issues loading the game: Ive had the same issue, but just closing and restarting the app tends to fix it. Not sure what causes the issue--maybe connection problems?--but I havent lost any progress from it, maybe just a few seconds while restarting the app.)
Not sure where to start, but this game does a lot of great things. Combat is simple to understand but still takes some strategy to do well with, and drawing symbols to strengthen skills works great for a touch screen mobile game.
Leveling your characters takes some grinding (characters require 2-3 different resources to level up, and you gain resources by completing levels), but once you beat a level, you can auto-fight it, making it much less of a pain. Rare resources/drops also increase in likelihood of dropping each time you run their level, which is helpful as well. It definitely takes some leveling or lucky character pulls to get through some of the boss battles, but it makes it more satisfying when you actually do beat them (though more likely than not youll be able to cruise through the following levels without much trouble until the next boss, at which point youll have to resource-grind to level again).
All in all its a great game. Interesting style, able to play for just a few minutes and still make some progress, and all-in-all an fun time. Give it a play and see if you enjoy it too.
Waarrior23 about Monster Mountain, v1.7