I enjoyed it.
I look foward to seeing more of your work.
For those who posted asking about cheat codes, and ratings:
I believe you need a S++ rating to receive a cheat code. I got that rating for finishing with almost full health, and a very fast finish, (as well as killing everything I found along the way.) I'm not sure if you have to get S++ as your rating though, there might be a lower one like A, or S that will give you a code. *shrug*
My suggestion would be:
1. Conserve health.
2. Kill everything.
3. Go fast.
4. Milk the energy beams for every point you can.