Not a bad game. It's fun, but it also easily gets repetitious after awhile.
There are a lot of flaws and bugs in the game that drags it down. The most irritating flaw is the experience system. It does not accurately reflect the difficulty between the various modes, or the monsters; and this makes leveling up the later levels a very long, drawn-out, process. Another flaw is the inability to buy weapons. I understand the limited slots for items, and the limited times you can upgrade durability points, but with the high difficulty of later areas on the map, and the slow leveling up system, it would only make sense to be able to buy the right type of weapons, instead of relying on random chance for them.
The bugs in the game, while annoying, don't really cripple the it in most areas, unless you don't have certain features to finish the criteria of the area, because of those bugs. The most common bug is the enemy staying in one spot. usually, this is a benefit to the player, but when you don't have the option to move because it was taken away because of the criteria of the area, there is no way to beat the area. Another bug that I notice only seems to happen on area 15, extreme mode, where sometimes hitting the armored dragon sends in into a ballistic ping pong ball that bounces all around the screen in a blur, constantly hitting you and the spike, eventually killing your entire party off. This has happened more than once.
Again it's not a bad game, and it's interesting, but the repetitious nature, flaws, and bugs, really brings it down.