Amazon denies it has a ban on Alexa skills referencing Google
The Amazon Echo 2
As you might imagine, the Amazon reviewer rejected the game. At first, Amazon said that the game was turned down because an Alexa skill "should not promote Google Home." Sounds like a ban to us. But soon, that was changed as an Amazon spokesman said that mentioning Google Home on an Alexa skill could lead to "customer confusion." According to the company, the original statement from the skill tester was incorrect as Amazon does not ban the use of brand names.
"We reviewed the skill and determined that the incorrect phrase could lead to customer confusion and did not accurately portray the skill functionality. The certification representative’s response was an error. We do not ban the usage of brand names, although we do strive to ensure that trademarks, intellectual property, or brand names are used properly."-Amazon statement
Still, if you are a developer working on a new skill for Alexa, it might not be a good idea to have the Google brand mentioned. By the way, there is a happy ending to the story. Mind Maze was eventually approved by Amazon and can be added to your Echo by clicking on this link.
source: TechCrunch
Things that are NOT allowed: