This is a pretty common problem I've seen in all the bases and buildings people post. A common mistake is to design without keeping perspective in mind, which makes people build things that look more like they belong in a side scroller game rather than the type of game they're actually going for (One that uses 3/4). People tend to draw things as if they were looking directly at it from the front.

What 3/4 Perspective is:
...a popular camera perspective in 2D video games, most commonly those featured in 16-bit or earlier console or computer games, and handheld games. Instead of using top-down perspective or a side view, the camera is rotated slightly. The advantage of this perspective is the visibility and mobility of a top-down game, with the character recognizability of a side-scrolling game.

Two of the most consistent examples of 3/4 perspective are in the The Legend of Zelda series of games on the Game Boy, Game Boy Color and Game Boy Advance and the Pokémon series on Game Boy Color, Game Boy Advance and Nintendo DS.
[source]



Basically if your base is looking at you, that would mean it would have to be looking up at the camera, not in front of itself.

3/4 Examples:




No flat buildings there right?

This is not the same as top-down view. In top down, obviously, the camera is directly at the top looking downward, meaning you would only see the tops of objects and structures. It's not the same as isometric perspective either, because in this case the camera is only rotated upward, where isometric is a view that's been rotated upward and to the left or right.

Basically, keep in mind that unless you're making a side scroller game, you're not looking directly at a person/thing, you're looking from a heightened angle.