*Disclaimer* This is not a thread to Lament the unoriginality of games. *Disclaimer*
As the name says, name the last 100% original game that you played. By 100% original I mean a title that did not borrow anything from anything that came before it.
And GO!
There are not more than five primary colours, yet in combination they produce more hues than can ever been seen. - Sun Tzu in The Art of War






