Keys "s"=save "l"=load "b"=back once
All units can promote on the eighth rank. One can also win by getting one's king and a friendly queen onto adjoining squares. Escaping from check takes precedence though.
The idea is by Doug Chatham. Click here to see his 42-square variant. I have adapted it to a standard board.
These are simple illustrations rather than strong opponents.
Bug reports? -- Thank you! Keep them coming!