I'm trying to use this on cave story + , but when I open the program it doesn't show anything besides a background, and there's no readme file to help, what should I do?

Yeah... it's supposed to have some text. I wonder why you're not seeing it... Hm... Is there anything uncommon about your system that you can think of?

Regardless, I imagine the randomizer will still work, on-screen instructions or not. Here's how you can use it:

1. Drag and drop your Cave Story folder onto the Cave Story Randomizer window. 
2. If the randomization was successful, you'll wind up with a folder called "data" inside Cave Story Randomizer's folder.
3. Overwrite the files in your copy of Cave Story with the versions inside that "data" folder. Don't forget to save a backup of the originals!

Still doesn't work, when I do that it just opens the same window as before.

The only thing that occurs to me is that I'm using windows 7...