You can play them any time you want over the internet. You can download them to your cell phone for a few measly dollars. Heck, sometimes they even come pre-installed on your computer... for free. So what could possibly compel someone to pay full price for a portable 2D puzzle game that looks suspiciously similar to Bejeweled?
In short - magic, monsters and multiplayer.
On the surface, upcoming PSP and DS game Puzzle Quest: Challenge of the Warlords does look and play an awful lot like something you've seen an awful lot of times before. There's a grid of shiny colored stones, two of which can be switched at a time. By choosing pairs that, when in each other's place, create three-in-a-row patterns, you eliminate pieces on the board and receive points.
But then things get different - and more interesting. The points aren't just points in Puzzle Quest; they're mana. And matching blue stones or red stones does more than just scratch a small puzzling itch; it gives you the power to cast water or fire spells (or wind and earth spells with yellow and green) on your opponent.
Yeah, no battling the clock or your recent best score... here, you compete against actual enemies, whether they be computer-controlled giants and evil knights in the single-player quest or a real-life human in the wireless multiplayer. The only way to win a board is to knock the other combatant off the board. You can whittle at their hit points by matching damage-dealing skull stones together or slash their life in half with a well timed magic attack.