Thanks a lot! I've used your latter suggestion and added a "full rules" section. And will work on better notifications later.
a few more ideas:
* jumping onto a field under attack sends the knight to a random new location instead of deducting points
* configurable board size with the number of black pieces adjusted. the classic 8x8 board with 16 black pieces could be one preconfigured choice
* multiple white knights.
* a random black piece moves after each jump of the white knight