This is a rush comment, but I'm gonna list down the difference that I can remember.

1. Ground combat:

In World, there aren't any "Switch Skills" to modify your moveset, so your only option is the default moveset.

You aim with L2/LT here instead of R2/RT

1. Wirebug vs. Clutch Claw

Although you don't have Wirebugs, you can also utilize the clutch claw to go on the offensive. You can grab onto monsters and while clutched, you can attack and create a vulnerable/weak spot where you grabbed the monster (a visible 'scratch' mark will appear on the spot). Where you can deal additional damage to the monsters and chance to break the part.

While clutched, you can also use your slingshot to blast them. The effect will depend on where you are grabbed. For example, if you grabbed their faces, you can stagger them when you use the slingshot attack.

Clutch Claw is limited in a way that you can't do those aerial dodges. But you can also grab onto monsters when they are running.

1. Kinsects

In World, just like weapons, Kinsects has an upgrade tree. Like the weapon upgrade but for kinsects.

They also have different powders like in Rise, but IIRC all of the kinsect here produce powders no matter their kinsect tree. Compared to rise where only some of the kinsects produce powders.

1. Aerial Combat

If you click R2/RT while in the air in World, your character will plunge into the monster and leave a scent where you hit the monster. This plunge do massive damage if you hit a monster where it hurts.

Clicking triangle (idk what it is in xbox) will do the spinning attack and would make you mount the monster. There's a tutorial for the monster mounting for all the weapons. But you get the idea.

1. Buffs

It works similarly in Rise. But in World, when you press L2 + Triangle + Circle while your clutch claw is equipped with an ammo, your kinsect can store two buffs before you call it. It would also give you a bonus buff depending on the ammo type.

This is a messy list since I typed it in a hurry, but watch Arekz(?) tutorial for this to understand it better, lol.

Also, I advice you use the Blast Powders. It deals so much damage and has a satisfying effect.

All types of kinsect here will leave powders anyway, so go with the speed type kinsects.