Pics from Kirby GC, The new Zelda, and Mario Baseball. Yeah, Mario Baseball.

[A Black Falcon]

So what I mean is Doom is 3D because it looks 3D to your eyes. Now the fact that, in playing it, you realize that there are NO "underneath the stairs" areas, and that whenever you go up or down, elevators are used or other things since it's impossible to have two different height levels directly on top of each other, shows you that in some ways the gameplay is 3D (a wall can get in your way and you can take stairs to get over it), but in a major way it's 2D (If you are on the "second story", the floor below you can't possibly have monsters on it, not until you, ego, lower the active floor TO that level, so in other words no creepy climbing down stairs and then suddenly a monster hiding under the stair case comes after you moments). Purely graphically, it's 3D because that's what it looks like except for the actual sprites, which are 2D layered in a 3D environment.

Exactly. Oh, it's also 2d because there is no height element to the game... that is, you don't actually have to aim up or down at things to hit them, only left or right... :D

Now with Duke3D, they actually allowed true 3D because, even though everything was still sprites layered in 3D space, you could actually be a floor above some real action instead of a floor above null space until you lowered the entire floor. Thus, they could actually add a spiral staircase that eventually looped above itself! Amazing!

Good point. I was referring to how Build uses sprites for the characters and stuff, but yeah, it does have real 3d terrain with layers and stuff and aiming so it's definitely a whole lot closer to it than previous efforts.

And big guy yeah I'm fine with 2.5D. Kirby 64 was like that in gameplay terms since while it was all just running in a single plane, sometimes it curved around mountains and stuff, and when you shot bullets, they also curved around. Also, if kirby tried using a straight edge to measure the curve, it woudl curve too, because ether is something that's intrinsically impossible to prove.

It's just a curving 2d plane... the polygons let them do fancy graphical tricks but don't actually effect the gameplay. In Kirby 64 it doesn't even have the impact of Goemon's Great Adventure, I'd say, for how much the polyagonal graphics affect the game...