A saccharine taste is the taste of saccharine. Saccharine is a sugar substitute. This is a figurative use. saccharine has come to mean overly sentimental or sickeningly "nice".
Google: saccharine Nintendo
You will find that the two are associated in the minds of many!
so in this sentence it has a negative meaning right? ntendo usually cranks out games that have a juvenile-centered theme, the poster found it childish and sickening?