I think that there is so many games, hundred thousands of titles so games can't be unique in 2018 like in 1994, because even if now now game will be unique... Still it uses something that we had seen in other games.

I think Unique game is completely new type of game. Games who had massive impact on next games like:
First Dota - Entire MOBA genre
PUBGy - Battle Royale games (to be honest h1z1 was first but King of the hill mode and PUBGy is built by the same person)
Doom - not first 3d FPS but have so massive impact

ect.