https://www.gamespot.com/articles/smash-bros-for-switch-will-be-playable-at-e3/1100-6458557/

Nintendo today detailed its plans for E3 2018, and among the most interesting details is that the new Super Smash Bros. title for Switch will be playable on the show floor. During show hours on June 12-14, you can visit Nintendo's booth at the Los Angeles Convention Center to be among the first in the world to play the highly anticipated fighting game.

Those willing to brave surely long lines will also get to play "a variety" of other titles, though Nintendo did not announced any specific games. The company also said that some of the "most noteworthy" third-patty games for Switch will be "featured across several Nintendo activities throughout the week," though it's unclear if these will be playable on the show floor.