In-game:

left and right arrow keys: move
up arrow key: jump
down arrow key: fast fall (not all characters utilize this ability.)

Z: attack
X: special attack

Menu:
Left click: choose stuff, lower battle time on character select screen & disable items on character select screen.
Right click: select CPU on character select screen, raise CPU level, turn on items & raise battle time.

There are many game modes to try out for yourself!

You have a regular Melee Match, which lets you fight a computer player on the stage of your desire.

The Single Player modes are as follows:
Classic Mode: Go through 5 stages, fighting foes, racing, then beating up hands at the end!

Adventure Mode: Go through various stages battling foes.

Target Test: A mode that needs no explanation.

Home Run contest: Hit the sandbag as far as you can!

Event Match: Mix it up! Play with certain conditions to challenge yourself!*

*Event 2 currently does not work

Myrio (Supah Mahryo Brothas)
N) Vanish
S) Slash
U) Gey Stahr
D) Rave Dance

Luee-G (Supah Mahryo Brothas)
N) Fireball
S) Torpedo
U) Jamp Panch
D) Green Cyclone

Yoshi (Super Mario World)
N) Eat
S) Ram into you
U) Flutter
D) Swallow

Bowzah (Supah Mahryo Brothas)
N) Flame
S) Gey Stahr
U) Whirling Fortress
D) Bowzah Bawmb

Goku (Dragonsball P)
N) Laser
S) Kamehameha
U) Warp
D) Focus

Hatsune Miku (Vocaloid)
N) Music Note
S) Mic. whack
U) Screw Attack
D) Kick

Edward Elric (Fullmetal Alchemist (2003))
N) Human Transmutation
S) Sword slice
U) Shield Burst
D) Alchemy

CD-i Link (Link: the Faces Of Evil)
N) Sword laser
S) Lamp Oil
U) Rope
D) Bombs

Silver (Sonic '06)
N) Dark Ball
S) Psychic field
U) Teleport
D) IT'S NO USE

[Beta] Lilac (Freedom Planet)
N) Roll
S) Comet Boost
U) Cyclone upwards
D) Cyclone downwards

Carol (Freedom Planet)
N) Wild Claw
S) Pounce
U) Motorcycle
D) Wild Kick

Sechizen
N) Spirit Bomb
S) Necromatic Bolt
U) Relocate
D) Resentment Blast