There are several genres of games that unfortunately are under-represented (or don't exist) on the DS. I'd love to see more strategy games. Whether it be real-time base building or something real-time tactical (a la Sid Meier's Gettysburg! or Close Combat), I think the touch screen can be utilized effectively there. It could also use some more turn based strategy that isn't tactical, like Age of Empires or Advanced Wars, but rather something like Civilization or Populous.
Also, why are there no baseball games for the DS? The touch screen could make a fantastic batting simulator. Instead of it being just a matter of timing like most baseball sims, batting could more closely resemble trying to hit an actual baseball. As far as I can tell, there are no baseball games slated to be released for the DS. More sports games in general could be a very good thing for the DS.
I just think there's a huge amount of gameplay available for the DS with the touch screen that is not there for other handhelds or even console systems. I've played tons of PC FPS's but generally hate console FPS's because I don't like using a thumb joystick for control, but Metroid Prime Hunters was enjoyable because I could play with the stylus which felt almost as natural as the mouse. Similarly, I think other many control schemes on PC games could easily be incorporated with the DS and it's stylus (though you'd probably have to get creative with the D-pad, shoulder buttons, and regular buttons). I mean, I'm all for puzzle games and side scrollers, but it just seems like there could be so much more.
Perhaps the DS is seen primarily as a kiddie device and won't attract quality developers to create great games in the genre's mostly seen on the PC, but if so that's a shame. Perhaps I'm just too stuck on PC gaming. But I hope we can either look forward to developers taking full advantage of the stylus or homebrewers to port more classics over.
/end_rant
