(re: What about new sequels?) Sure, the GBA platform has a lot of side-scroller games, or other types of games that aren’t realtime 3D. Is that because those games work better on a small screen? Because the GBA’s processing power is better spent on side-scroller games? Because Nintendo (as opposed to PS2 for example) makes more side-scrollers? I’m not always up on the platform market, but I have a GBA (which I love), and you’re right about the type of games.
As for 2D adventures, large companies won’t touch them anymore. You’re right. And thanks for the insight about the programming side of things. You’re also right that there hasn’t been a true realtime 3D adventure game. Either new “adventure” games debatebly do not fit into the genre, or they use pre-rendered backgrounds.
I agree that there is fun to be had in 2D that doesn’t work as well in 3D. I also think though that there is potential for realtime 3D adventure. Watch for the KQ9 fan game. It should be true to form as an advenure game, while being realtime 3D (though I *think* the camera angles are fixed).