The representation, based on photographs of the couple in a sports event, has somere semblance to William but almost none with his fiancée.
Royal observers said she looks much more robust in the coin of what she is in real life.
“This coin has a historical importance, it seems ridiculous to do it in a wrong way,” said Majesty magazine editor in chief, Ingrid Seward, in a quote on SkyNews Web site.
The design was approved by the 28 years old couple and William’s grandmother, QueenElizabeth.
The Royal Mint, which produced the memorabilia, said they had no intention on changing the design.
The Royal Mint has created many medals and commemorative coins to mark special occasions, including the 2012 London Olympics along with other royalty events, but this is the first time that it creates a coin to commemorate a royal commitment.
The coins come in silver and gold, it costs between 9.99 and 1,550 pounds (2,400dollars).