To preface this review, I have beat the game. This review is not out of frustration for not being able to accomplish that, but it is out of frustration from the game in general.
For a match 3 game the concept is novel, adding a requirement of matching specific tiles to progress.
Unfortunately once the novelty wears off, it becomes a chore. And the novelty will wear off, because the game is stacked against you in multiple ways, and requires you to lose repeatedly to complete tasks and buy upgrades (which soon become an artificial barrier to gameplay) before winning it even becomes possible.
The main barrier to fun in the game is the manner of losing - not the inevitability, as with Tetris, but the speed at which it can happen. Every obstacle requires a specific type of match - attacks or keys - and the game can at whim decide to deprive you of these, leaving you helpless to do anything but wait until defeat.
Other problems with the control system compound this. For instance, sliding the tiles is not well designed. If you click a tile, it can only slide by the first direction the mouse moves. So if you want to drag a tile upwards but your mouse moves a LITTLE to the left first, your tiles will try moving left and right instead. You can try again while the mouse button is held down, but you've lost that time.
The matching detection is not great either. When you line or nearly line up a match, their tiles illuminate, however when you let go the tile you're moving can fit to an adjacent space, meaning the match does not occur and you have to start again. Once more, this costs time.
The game needs resource management - trying to keep a healthy number of attack tiles and keys on the board at all times to be ready for any obstacles that arrive, but a couple of things ruin this as a concept and make the game even less fun.
The monsters - particularly boss class monsters - require a LOT of matches and items to defeat, during which time you're losing time AND they hit you which also costs a nasty chunk of time. It goes without saying that despite the whole upgrade system, matching attack tiles is just not effective enough to keep the game balanced.
The game can and does throw numerous amounts of the same obstacles at you consecutively, such as two chests, a door and then another chest. Even if you kept a healthy number of keys available at the start of this, you probably won't have enough to get through it all which leads to a lot of lost time and defeat. The same applies to multiple tough monsters.
Matching tiles or using an item JUST before you arrive at an obstacle will cause it to be wasted. There's no tolerance whatsoever. This can lead to situations where you're not blocked by an obstacle, and too afraid to do anything because you don't want to lose the matches you can see available to you. This is contrary to the game's advertised element.
Finally, when you match tiles, more appear which can result in combos. Normally in this kind of game these are desirable, but in this game they can and will punish you by decimating a resource you can see yourself needing soon - for instance, if you're fighting a monster with a chest behind it, a few keys may fall in during the fight, matching with the ones already on the board and severely depleting the keys. Then when you win the fight you won't be able to deal with the chest.
Furthermore, when newly-fallen tiles create combos, this takes time during which you are unable to slide any tiles to make more matches. This results in awkward situations where you can see multiple matches you want to make but are unable to do so because a useless combo is ongoing and killing you in the process.
You do get a very limited number of items, but most of the time an item does not even clear one of its respective obstacles. After a few hours of play to finally be able to challenge for the game's namesake 10,000,000 points (yes, you need to play for a few hours before winning a game even becomes a possibility), key items will not be enough to open a three-lock chest or door, and you will need at least three damage items to defeat a single monster.
This game had promise, but its execution is disastrous. Its visuals and music are very fun for a few hours, but they do not last the extended periods of time demanded of you when the game becomes an unfair and repetitive grind.