Great idea, with flaws
I love the three-headed dragon idea, and the idea that the three heads are individualized even though they are part of the same creature. Some critical comments:
- Other than the robot's chest-light shining onto the hill, there's very little shading and many features, though detailed, seem really flat.
- Cyborg-head looks distinctly anime, Android-head looks more like a painting, and Robot-head looks somewhere in between. Meanwhile, the moon looks like a pencil sketch. This gives the piece an "unfinished" feel, even if it's done.
- From middle-right to lower-right looks really blurry and unfinished. What happened there? It's missing the detail of the rest of the piece.
- There's no uniform sense of scale. Those pine trees look 50 feet tall, except they're about the same size as 5 steps on the stone stairs in the lower-middle, and they're also about the same size as the stones in the path itself. I'm not sure if this dragon is 3 stories tall, 30 stories tall, or taller than the Sears tower.
I think you've got a great idea here, and you should keep playing with GIMP, as it is really powerful. (Although I think your computer has problems if you can't get Photoshop or GIMP to run correctly.)