It's a nice concept however the puzzle minigame takes away too much from the actual tower defence part of the game.
All you end up doing is solve the puzzle, hastly place turrets and repeat.
You barely get enough time to read the magic stones effects to decide which tower to place them in, which tower to prioritize upgrading and you constantly have to mouse over new gear and the currently equipped ones to see which one is better and here you again don't have time to read any of the additional effects/+stats they give, you only have time to focus on the highest number and swap them out instantly.
And just like that a round is over.
99% your eyes were on the puzzle field and you couldn't see any of the monsters, the map, the fighting or any animations as you have to constantly solve the block puzzles in order to gain any materials/orbs/equipment.
This makes the puzzle part feel way too oppressive and almost stressfull as you can't afford to pay attention to any other part of the game than the puzzle solving.
Less puzzle solving, more TD focus would have made this game better in my opinion.
Too bad that I can't really give feedback to the graphics/art style as all I saw were those blocks I had to move :I