You can click almost everything. Some items only have descriptions, others can be added to your inventory. However, you can only carry one large item at a time.
Use Ctrl to toggle text windows during conversation. Right click also works, but may accidentally select something when there's a choice on screen, so Ctrl is recommended.
When you see a goblin statue in the upper left, it means there are multiple images. Use the left and right arrows on your keyboard to flip through them. Click the mouse to exit.
