D3's "Puzzle Quest: Challenge of the Warlords" was one of the best games of 2007.  The way I described its Bejeweled-meets-RPG formula to others was if someone had said "You know what this crack is missing? Heroin."  It was addictive but more importantly, it was fun (without the death-mix a crack-heroin cocktail would likely cause).  Yes, you would lose hours upon hours of time going for just one more quest, but the game was so perfectly balanced that while luck was a factor, you could temper it by building up your skills, training your mount (a tamed beast you rode around on—yeah, still sounds like slang), and crafting new weapons.

While the sequel, "Puzzle Quest: Galactrix" contains all those elements, it's terribly unbalanced to where the gameplay is addicting, but no longer fun and eventually just frustrating.

Since there is an RPG element, there has to be a story and like "CotW", it's the most generic writing you can imagine except instead of being set in a fantasy-world, it's moved to sci-fi.  However, while "CotW's" story was certainly one its weakest points, it looks like Shakespeare compared to what they came up with for "Galactrix".  In "CotW", you had more characters classes to choose from and you even had a few options in choosing your apperance.  This time, it's just generic male and generic female.  Furthermore, members of your party were gradually introduced and they all offered you benefits when in combat against particular enemies.  Not only is that completely lost, but your entire party is thrown at you at the beginning of the game because this time around, rather than serving a strategic purpose, they're simply tutorial tools intended to introduce you to the simplistic gameplay elements you encountered in the first game and repurposed for different tasks.

I give D3 credit for trying to change up the central gameplay of falling gems.  They've now introduced "gravity" where you have hexagonal gems can be aligned in three different directions and they can come from six different directions rather than just falling from the top of the screen.  As far as this gameplay element goes, it's great fun, works perfectly and is the best difference from the previous game.  Unfortunately, everything else goes awry.

"Galactrix" falls too much on the side of luck.  It's not just when you're cheaply beaten by your opponent when he keeps getting mines (direct damage gems) to line up and you can't even get in an attack.  When you do it to your opponent, you no longer feel like you bested him through clever use of aligning gems, spells, and how you crafted your character.  You feel like you got lucky and it's highly unsatisfying.

There are also just a lot of weird challenges that take away from the ingenious puzzle battling of the first game and just turn it into standard Bejeweled but with the gravity mechanic and some constraint like clearing a certain number of gems or getting rid of specific gems under a time limit.  One of "CotW's" flaws was the amount of random battles but "Galactrix" takes it too far in the other direction and you're rarely battling unless you choose to (in which case you're just grinding) and when it comes time for the battles mandated by the storyline, you're not only horribly outmatched, but your opponents have access to weapons and abilities that are unobtainable to you. 

The game also comes up short in presentation when compared to its predecessor.  While this is a DS game and will only look so good, "CotW" had some very nice flourishes that made you feel triumphant.  The music was excellent (although the three tracks eventually became so repetitive that you just had to switch it off from familiarity), the sound effects were delightfully crunchy like when you smashed three skulls together and dealt some serious damage to your opponent, but best of all was the royal cry of "You are victorious!"  I would love to hear that in my daily life and little details like that are just completely forgotten this time around.

"Puzzle Quest: Challenge of the Warlords" was successful not only because it combined two inherently addictive genres but because it gave you numerous ways to play the game so that even if you weren't able to see every pattern or if your opponent got a lucky run of gems, you still had options at your disposal to best your rival.  That's all missing this time around and while the gravity mechanic is a nice change-up, everything else has gone horribly wrong and left "Puzzle Quest: Galactrix" as one of the biggest gaming disappointments of the year.