You must connect a total of 500 Launchers for this achievement. Press + to perform a Launcher. Launchers are vital attacks that can be used to start punishing air combos by knocking your opponent into the air! These can also be initiated by inputting any 4 hit combo. When performing combos of more than 3 hits, your 4th hit will automatically be a Launcher.
By pressing and simultaneously, you will send your opponent flying into the air and automatically tag in your standby character, allowing you to continue with a powerful combo!
Since Launchers are such a common staple to the game's mechanic, this will unlock naturally over time while playing or boosting online matches or while playing Arcade Mode. You can always set up a 7 round, 2 player versus match and spam them against the 2nd player. Switch them out once their health gets low and repeat on their partner until you K.O them and repeat. You should average 15-20 Launchers per match! This will unlock after the match upon executing 500 Launchers.
To check your progress for this achievement, go to Player Data at the main menu. Select Player Records and scroll down to see how many "Launchers Connected" you have to keep track.