Just to experiment, but yeah, I would eventually like to make my own engine, not necessarily to use it, but to learn how everything works behind the scenes. Seems like a useful skill to have.
Also, as far as I have tested (may be wrong), in terms of performance, Dictionary > Script > Scene, so since I was going to put it up on the web and there are lots of enemies (10 * level), I figured I would give it a go