There are plenty pascal-libraries available. Coding with pascal is harder than using the drag-drop gamemaker interface, but it gives you tons of extra possibilities.
You must ask yourself some questions first:

>> Do you want to use OpenGL or DirectX?
with openGL you can make cross-platform games, and it also tends to be a bit easier to learn. DirectX is harder and windows-only, but is the standard for commercial games. DirectX also includes sound, input and networking modules.

>> Do you want to make 2d or 3d games?
2d games are a lot easier and don't require as much math as 3d games do.

So here are some lib's for ya :

UnDelphiX (2D using Direct3d)
Asphyre (3d using directX)
Necro3d (3d using DirectX)
pascal-headers for SDL (OpenGL based... not quite sure :? )
GLScene (3d with OpenGL)

You could also start from the scratch by using
Clooties DX headers or you could start learning openGL.
But this is a lot harder and requires much time.

Good luck