Luigi is a playable veteran unlockablecharacter from the Mario universe in Super Smash Flash. He is one of four clone characters in the game, borrowing his moveset from his brother, Mario. Moreover, the creator of Luigi's sprites is also the user Xander, who picked a Mega Man 8-like style for the Mario Bros.'s appearance.
This section requires to be rewritten or expanded.
The information is not outdated nor incomplete, although it can be rewritten for a more formal explanation and better clarity. It may require an expansion going further on missing details.
Luigi has excellent horizontal movement, high jumps, and good KO power. He has easily the best projectile in the game, the Fireball, due to its very fast speed and firing rate. The Luigi Cyclone is a good turtling move, as it comes out fast, surrounds Luigi on both sides, has a long active period, and has instant-KO properties.
Like Mario, Luigi does not have any real weaknesses, other than his lack of a Momentum canceling attack. This lack of downsides makes his strengths appear even more pronounced, as he has strong matchups across the board, resulting in his high placement.
Shoots a fast-moving Fireball. The Fireball travels in a straight line, without being affected by gravity. Comparing to Mario's fireball, it is slower, allowing it to deal more hits at a time.
The attack's hitbox is bigger, giving Luigi better coverage.
It has slightly more range above Luigi and less range in front of him.
Luigi's hurtbox is noticeably wider.
Other animations
Luigi's standing and flinching hurtboxes are slightly wider and notably taller.
His crouching hurtbox is slightly wider.
His running hurtbox is a bit taller.
His falling hurtbox is somewhat off-center.
Trivia
As it was with the case of Mario, Luigi's original sprite sheet by Xander actually has elements that were omitted from SSF due to limitations, such as Luigi hitting with his rear or the coins from Super Jump Punch.