Playing as a Gigantopithecus is very similar to playing as an human, but there are some significant differences. So here are some tips on how to play.

The custom made spawnscreen that lets you only choose between human or gigantopithecus can be enabled in the Admin Menu under the General Settings.

Engrams
As a Gigantopithecus you can unlock all engrams humans can. This allows you to build the same structures and craft the same tools. However not all human items can be used by the Gigantopithecus, for example sleeping bags, beds and guns. For some of these there are alternative engrams made specifically for the Gigantopithecus. For the Gigantopithecus the following engrams have been added:
-Gigantopithecus Spear (melee only)
-Gigantopithecus Torch
-Gigantopithecus Sleeping Bag
-Stone Rock (throwable)
-Siege Boulder (throwable)
-Tranq Spear (throwable)

Inventory
The inventory consist of two parts the Gigantopithecus and Transfer (player) Inventory. Crafting is all done in the Gigantopithecus inventory. To transfer items to other inventories you need to place the items first in the Transfer Inventory and from there open the other inventory and transfer the items in there. You can also check the Auto Transfer Items option.This will automatically transfer your inventory item to the Transfer Inventory when looking at other inventories, when exiting those inventories the items will transfer back. You can place structures using the Place Selected Button in the Gigantopithecus inventory or place them as normal from the Transfer Inventory and hotbar.

Water
New to the Play As Dino mod the Gigantopithecus has a working water stats. This means you have to manage your water supply. You can refill you water by standing in a body of water or drink from a waterskin.

Weapons
The Gigantopithecus has the option to equip weapons and tools, these can be equipped inside the inventory or quickly be switched out by pressing Alt and selecting one from the menu. Make sure the weapons are placed in the Gigantopithecus inventory. The Gigantopithecus can only equip weapons that are melee only so unfortunatly no bows or guns. The equipped weapon with change the damage/harvest output of the Gigantopithecus. By default the LMB attack can harvest berries, thatch and wood, the C attack can harvest fiber, stone, meat and hide.

Throwables
You can throw several different projectiles by holding RMB. Releasing will throw the projectile at your crosshair, you can cancel the throw by jumping or attacking. You can quickly select the projectile you want to throw to by holding R. Make sure the throwables items are placed in the Gigantopithecus inventory. You are currently able to throw the following projectiles:
-Spear (normal)
-Tranq spear
-Bola
-Stone Rock
-Grenade
-Boomerang
-Siege Boulder

Taming
You can knock out creatures by equipping a club or hitting it with Tranq Spears. After that you can place taming food and narcotics in its inventory to tame it. For passive tames you need to put the taming food inside the Gigantopithecus inventory and press E when looking at the creature. You don't have to put the food in your hotbar. When you tamed a dino you can equip it with a saddle to ride it. You are able to ride any dino humans can, but you can't use your weapons when riding the dino.