I open big complex applications on a daily basis so I'm not afraid of opening another one to edit my porftolio. The poser comparison isn't apt, CSS & HTML have no application in my line of work it's just something to learn and eventually forget. Sure, you can make bread from scratch but don't argue against sliced bread.
boxes and barrel are the bread and butter of games; maybe try start with some of them. CheeseOnToast gave a good suggestion. Regardless of what you make, keep it simple.