NES system modification
Wally Bear and the NO! Gang, as an unlicensed Nintendo Entertainment System game cartridge, did not work on systems manufactured after October, 1990. Newer NES consoles, with a "revision 11" circuit board, contained hardware protections preventing unlicensed game cartridges from running properly. The manual explains this (along with a no symbol above 'Rev. 11', and the title "Just Say NO!"), then provides instructions on how to modify an NES game console to bypass Nintendo's hardware protections.
The Wally Bear and the NO! Gang Club
The game manual for Wally Bear and the NO! Gang contained a cut-out postcard that allowed the purchaser of the game to join the Wally Bear and the NO! Gang Club. The postcard could be mailed to a post office box in Fogelsville, Pennsylvania (the address of Edutainment, Inc. at the time) along with $3.50. A club member received a poster, stickers, and a bi-monthly newsletter with the "gang's adventures, and products with special membership discounts".