I'm sorry Jorge, but other than the angle they are turned, and the fact that they are colored different, I see no difference between the two (although in my engine based on where you are the clock tower DOES angle different like in the pic and like in SOTN).
My experience with z-buffering (I assume that is what you mean by Z-depth, or am I mixed up?) is basically to make stuff look like it is coming at the screen, right? But in this case, I would have no reason to make the tower appear to come closer to the screen?. I did use z-culling on the object to make the faces appear correct, but I never tried any z-depth stuff with with the tower.
Maybe it's just that you have so much more EXP. with 3d than I do, but looking at SOTN and my game, I don't see any issue depth wise at all. I am actually amazed at how great your tower looks in game; it makes the original one look choppy and trashy.
But if I can find a way to make it look even better (which you are making helpful suggestions for) I am all for it.
Oh yeah, the tower looks so awesome. However, there's a basic concept of perspective that it's quite difficult to express without going into a big lesson. But I will try anyways.
Say you have an object like a box. The box is about the size of your fist. You hold it about one foot away from your face such that the front face is facing you, almost like a square. Then you move it to the right side of your face. You will notice that the box will show its side face, at an angle.
Now, say you have a huge box. Huuuuuuge, like the size of a giant square building. However, it's quite far away from you; far enough that if you look at it, it looks the same size as the box you held in front of your face earlier. The difference? Well, the difference shows as you move the building to the same 'relative' location as the box, so that it looks like it's in the same position. The perspective angle will be different, and it's what tells our brains the relative spatial location and size of an object.
The way you have the clocktower right now, as you move Richter to the left, the clocktower slowly scrolls to the right. However, there is no perspective angle at all. This would lead people to believe that it's an incredibly huge object that's very very far, while in fact it should look like a reasonably large object that's somewhat close to the player. Only by having a perspective angle (achieved either with a horizon like, or by scaling the object so that it's smaller and then moving it forward, toward the camera, so that its perspective changes) will it look like the SotN version.
It's a simple but very important concept.
Since I don't know how you're programming the scrolling, I'm guessing:
1. you don't have any, or you do not have properly implemented, vertical scroll variables for the 3D objects. Something like 'orthogonal scroll ON' or something, that cancels any depth of angle... again, just a guess.
2. you have positioned the object very far and have scaled it very large (unlikely)
3. have never set up a horizon line for relative perspective (I doubt GM does that).
I'm leaning towards 1.