I will play around with the layout, if I can get it to look good, I'll give it a go! I do have another game, Greeting Card Guard, that uses the bifold (greeting card) format for the game board but not for the rules.
Viewing post in Moving to trifold pamphlets for campaign & rules comments
A couple of possible examples for inspiration:
1) Bright Hammer has some nice looking "one-page" zines (especially the Bestiary) which could theoretically have been converted to a bifold pamphlet by flipping sections around.
2) Most of the Cheapass Games rules are bifold pamphlets.