I bought the game based upon other reviews, and I'm pleasantly surprised. It only takes a minute to start picking up how the game works. However, while the learning curve is nice, the lack of a help file or thorough wiki might discourage some.
The graphics are colourful and cute, and almost all items are easy to understand from the pictures. The flavour/story text has a few grammatical errors, but are only mildly distracting.
You essentially explore a dungeon by clicking squares on a grid, which contain either empty space, monsters, traps, or other places like shops or shrines. Standard RPG stats are used, like attack (ATK) and dexterity (DEX), with levelling up and items granting bonuses or debuffs.
It's nicely challenging, and somewhat addictive, so you can easily sit down for a quick game and end up sinking a couple of hours before you realise it. More complexity is added because you die, over and over again, and restart the dungeon without losing your gold. Each time you restart, you can choose to spend money in order to unlock runeword bonuses, add experience and health bonuses, or buy new items to aid you right from the beginning. Furthermore, you can unlock new character types, who have completely different styles of play.
One star was deducted for the cumulative lack of in-game info or help file. I feel that understanding how things are supposed to work can help you strategise better.
Overall, a nice little surprise.