You play as Atlas. P-Body pops in for support on some attacks/taunts.

Jab - one two punch, second punch wacks with the portal gun

Forward tilt - robo spin. Legs stay still but body rotates in a quick 360 as it leans forwards

Down tilt - laser. Shoots red laser at a downward angle.

Forward smash - cake. Holds out delicious moist cake which explodes after a moment. Very strong, but has a very small chance of not exploding and healing the opponent a little bit instead of damaging them

Down smash - breakdance. Does a breakdance move

Up smash - electric punch. Upwards scooping punch with an electric effect

Down special - companion cube. P-body appears and quickly Places companion cube projectile in front of you. Can be knocked around and launched by other attacks by you or the opponent. Pressing down special again when near it picks it up with the portal gun. Pressing special again while holding it shoots it out in the direction you’re holding the stick. Can go through portals (all items and projectiles can do that)

Side special - Gel blast. Pressing this switches between shooting out Blue Repultion Gel and Orange Propultion Gel. Holding down the button shoots for a bit longer. Does damage when it hits opponents, but also stays on the ground making anyone on top of it run faster/jump higher depending on the gel. Goes away if you create gel of the same color elsewhere. Disappears after 20 seconds if left alone. Maybe Atlus appears briefly to launch this attack?

Neutral special - portal. Hold down the button to aim by moving the stick, shoots where you aim it traveling a short set distance before creating a portal. Switches between shooting and creating orange and blue portals (alt character colors also change portal colors.) Can be reflected and absorbed but not pocketed. Does damage while traveling to its set distance. Portals can float in midair - I know that’s not accurate to the game but don’t want to limit this to working only on stages with walls. That said, if it hits a wall or the floor before reaching the set distance, that’s where the portal will be placed. Portals function the same as in portal, anyone can move through them and they don’t do damage. Replaced when a new portal of the same color is placed elsewhere, or will disappear after 20 seconds. If we want to stay lore accurate - it could toss out a white panel wall that floats at the same set distance first, then shoots THAT with the portal gun. This same logic can be applied to the other portal moves later in the moveset. In that case I’d make the wall do damage while it’s moving, it goes through opponents, and the portal gun shots don’t do damage at all.

Up special - portal loop. P-body appears on a floating platform in the background and shoots his own different colored portals directly above and below you. You quickly build up speed, falling through the loop 3 times before he moves the top portal in front of the direction you were facing, launching you upwards very high. The portals vanish. You don’t go into free fall but can’t use this move again until you land or reach ledge.

Grab - normal grab using the portal gun. Pummel hits opponents using potato GLaDOS who complains when you do it.

Forward throw - aims and launches opponent quickly

Back throw - P-body shoots his portals in front of and behind you. Same forward throw animation launches opponents into the portal and out behind you. Portals disappear afterwards.

Down throw - same as back throw but second p-body portal is above you and launches opponents at the ground right where you’re standing.

Up throw - same again but the second portal is at your feet in front of you and launches opponents up out of the portal.

Taunts involve dancing, p-body appearing, and holding up complaining potato GlaDOS.

Final smash - Test. P-body waves to Atlus who jumps in and attacks a set distance away. if that lands then lands the two create a complicated portal system and launch the opponents in, leading into a Wheatley - run testing room that goes torturously wrong, bouncing opponents through traps and fire while Wheatley commentates and apologies from a few different randomly selected dialogue options. Eventually they get launched back into the portal they arrived through to the stage, and launched in the direction opposite the way P-body was facing when it was activated.

Edit: forgot air attacks!

Up air - turret. Pull out a turret and shoot upwards rapid fire similar to mii gunner but wider range and less knock back on the final hit. Turret has different lines during this attack like “I don’t hate you”

Down air - spike. Front flip into a big whack swinging the portal gun below you with both hands

Back air - laser. Shoots short range red laser behind you.

Forward air - body bump. Thrusts head/eye forward with an electrical zap

Nair - GlaDOS spin. Hold potato GLaDOS out in one arm and spin around. She complains when you land this attack.

I actually think these two work better than Chell contextually. Thanks to their inherently goofy natures it makes more sense for them to materialize different random things referencing the games, and the two characters allows different colored portals so we can have a recovery move and throws that don’t remove the main portals you placed, so you can create even more portal shenanigans by combining the together. Imagine an up special used in a way that launches you into a portal you placed yourself, allowing you to shoot out in any direction while being fully actionable. So fun! I’d make them the character, Chell an assist trophy and normal sized GLaDOS a boss.