It's hard for me to deny I had fun with this game, as I did play it for hours, and have finished it. However, the game has many flaws on many levels. First of all, the user interface has its problems: stylus taps sometimes go unnoticed, which is very frustrating when you lose precious seconds in a timed game or inadvertently make illegal moves for which you are then penalized. Secondly, the game seems to rely heavily on chance, which is felt the most during timed games (which are not optional): there's not much else to do than to try and try again in the hope the right blocks will appear at the right time often enough. Thirdly, the game feels very sluggish due to the fact that it saves your game every 5 seconds, and the load screens do not help either. The story was rather uninteresting, I ended up just quickly tapped through it. There are some good ideas (such as the different races/factions) but they gave me a general impression of being heavily underutilized.
Of course, it's not all bad. Some of its predecessor's flaws have been remedied: more interesting spells/ship upgrades which lead to different gameplay, resources are better handled (mining instead of the mindless running around visiting cities), the constantly respawning enemies on roads have been replaced by leap gates needing to be hacked (generally just once but occasionally a leap gate turns off again and requires re-hacking). The minigames are variations on a single concept, but require a sufficiently different approach to winning so as to keep it interesting.
To summarize, the game is far from reaching its full potential, making it a disappointment. As mentioned before, I did finish it, meaning it must have some qualities, but I doubt I'll ever play it again. I'll be waiting for Puzzle Quest 3 though, hoping it'll be less of a letdown.