Pokémon Sun and Moon reportedly contrast not only in the time of the day but in its story line as well. Moreover, it should be noted that there are Pokémon monsters exclusive to both Pokémon Sun and Moon. Additionally, the games have also been noted as a trainer's paradise not just because of the Alola setting but but because of online features and overall updated feel as well.
In Pokémon Sun and Moon, there are no Pokémon Gyms. Instead there are Island Challenge Trials. Additionally, it is believed that the Totem Pokémon is also a little different. However, the main difference between Pokémon Sun and Moon can be derived from their names. Note that there is a time difference of 12 hours between Pokémon Sun and Moon. Moreover, Pokémon Moon is said to reverse day with night and night with day.
Furthermore, several Pokémon creatures are exclusive to Pokémon Sun and Moon. For instance, Lycanroc Midday Form, UB-O2 Absorption, Solgaleo, Alolan Vulpix or Alolan Ninetales, Braviary, Gible (Gabite or Garchomp), and UB-04 Blade are Pokémon Sun exclusives. On the other hand, Lunala, Alolan Sandshrew or Alolan Sandlash, Lycanroc Midnight Form, Beldum (Metang or Metagross), and UB-02 Beauty rock the reversed clock of Pokémon Moon.
Meanwhile, Pokémon Sun and Moon are also said to be a trainer's paradise. First off, Pokémon Sun and Moon features an all new creative region called the Alola Region. Note that breeding is also easier in Pokémon Sun and Moon. Furthermore, Pokémon Sun and Moon has also been noted as the best among the Pokémon franchise showing new versions of old Pokémon.
Pokémon Sun and Moon reportedly have a great interface and online features as well. However, Pokémon Sun and Moon are said to have a terribly vapid writing. Moreover, there are reportedly lazy and borderline offensive villain in Pokémon Sun and Moon. Finally, there is suffocating linearity and handholding too. Watch the differences between the two here: