Well you can, if you move the scene with SetViewOffset the world y will be less than 0 but you need to employ the proper mechanics to determined mouse position or click/tap position, especially on mobile
please note ....
AGK Help wrote: "This is an emulated input method that uses whatever device inputs are available to produce a screen pointer. If the device has a mouse then this returns the current X position of the mouse. Otherwise the AppGameKit will check for a touch screen and, if found, will return the X position of the most recent touch event."
so if your last tap was at 100x100 and you call GetPointerX it will return 100 on mobile and the mouse x position on desktop .... its not that you cant go y high you just have to use the correct functionally IE: (GetRawTouchLastX/Y and WorldToScreenX/Y and ScreenToWorldX/Y)
Touch positions are in screen coordinates and sprite positions in world coordinates, you need to take this into account when using a world area bigger than or outside of the screen area