ILLEGAL: B b1-a2 on turn 6:
There was no B on b1. The piece on b1 is a N.
Go back with your browser's BACK button, reload the page, and try again.
For diagnostic purposes, here is the full movelist:
1. N h1-g3 
1... p b7-b6 
2. P f2-f3 
2... p g7-g6 
3. P d2-d4 
3... p f7-f5 
4. B c1-f4 
4... n h8-f7 
5. P a2-a3 
5... b f8-g7 
6. B b1-a2 
6... r g8-f8 
7. N f1-e3 
7... p e7-e6 
8. N e3-c4 
8... p d7-d5 
9. N c4-e5 
9... n b8-d7 
10. Q g1-e3 
10... n d7-e5 
11. P d4-e5 
11... q e8-e7 
12. P c2-c4 
12... p c7-c6 
13. P b2-b4 
13... p g6-g5 
14. B f4-g5 
14... n f7-g5 
15. N g3-h5 
15... n g5-f3 
16. P e2-f3 
16... q e7-h4 
17. K e1-d2 
17... q h4-h5 
18. P h2-h3 
18... p f5-f4 
19. Q e3-d4 
19... b g7-e5 
20. Q d4-d3 
20... b e5-a1 
21. R d1-a1 
21... q h5-g6 
22. Q d3-e2 
22... r f8-g8 
23. R a1-g1 
23... q g6-f6 
24. B a2-b3 
24... q f6-d4 
25. resign
In case there is a bug in the code, the settings file can be edited at /play/pbm/play.php?game=King+to+Bunker+Leap&settings=Asymmetric&submit=Edit