Only SINGLEPLAYER works for now. When you see the words "TAP!" quickly spam Z and X as fast as you can. When you see a red "!", quickly press C to stop your counter from going down. The bot's counter is hidden until after he strikes, so you just have to hope you can tap faster than them!
Based on that one minigame from Kirby Nightmare in Dreamland I actually went back and worked on this for about an hour to make it a playable game, it's nothing special but I hope its at least somewhat enjoyable now. (UPDATE: I actually continued working on this for a bit on my main, click on the remix below to play it.