When my daughter was one or two, she was more interested in the keyboard than anything else. I solved this by finding an old (indestructible) apple keyboard (with no cable) and letting her have that. She was happy to imagine the rest of the computer.
She still has that keyboard now (at six) and has been known to build her own "PC" out of boxes and other things.
There are many ways to foster interest in what you do, but there's no need to rush it. They'll get there when they're good and ready.
Adding features does not necessarily increase functionality -- it just makes the manuals thicker.