First X game to feature a jet bike.
As an Easter Egg, X can learn the Flaming Dragon Punch that Ken uses in the Street Fighter games.
There are three X-Hunters in the game. By defeating them you can get parts for Zero, who was killed in the first game. Getting all three parts results in Zero rescuing you from a fake Zero in the final level. If you fail to get them, you will fight Zero prior to Sigma.
The final stage of the game is the same stage you fought Magna Centipede in earlier in the game.
Of the SNES Mega Man X games, this is the only one in which Vile doesn't appear.