In my opinion, this game has four massive flaws:
1. This game from level 1 to 6~7 it's funny, but afterwards it becomes a hell of grinding where you end up dancing around a mob of enemies for 10 minutes, dying, and never having enough money to buy the upgrades you need.
2. The timed mission (from the side quests) are almost impossible, and if you choose to pay for runes, you usually spend more than what you earn with the reward. I think there is no purpose on limiting the level for those missions.
3. Two potatoes and a carrot would be far more useful and intelligent than your "partners". This obviously applies to the side-quests, too.
4. The art style lacks any kind of innovation, relying on copying from... well, almost everywhere (DotA2 and Blizzard are the biggest examples in my mind right now, and it's not just a cameo).