Beta tester testing a beta:
Since this is only a demo, I'll comment in relation to the stage of development it is in.
The art is nice enough for sprites, obvious inspiration from Pokemon, I liked the scenery. The Oak character was detailed, and looked the best out of the demo. Though if you have time, I'd really add some colour, unless you are going for a gameboy/high feeling.
The controls need work. You lag around the outer rim, and you speed along like crazy in the middle. I realize it's a demo, but you need to get the basics down first.
I can see how this would make a clever full game, but you might want to check some forums or even ask for some collaborative help.