The star of today's Nintendo Direct was Mario Tennis Aces, which the company announced would be released on June 22. Along with it, Nintendo also confirmed the game would have a "swing mode", which is basically the closest you'll be able to get to Wii Tennis on the Switch.
According to the Direct, Swing Mode is the casual oriented mode. Using the motion sensors in the JoyCons, you'll be able to serve, slice, hit forehands and backhands, and lobs in the Wii Tennis-esque mode. (Top spin shots aren't available, however.)
Mario Tennis Aces will have an online 1v1 tournament - a beta, effectively - before the game's release on June 22.