Content Warning, but you're your Minecraft self. Everything Minecraft is read from your own Minecraft: Java Edition while you play: its textures, mobs, sounds, font, title screen and your skin.
Minecraft title screen with a Survival / Creative switch
Your skin on a Minecraft body, wearing your armor and holding your item, for the whole crew to see
Minecraft movement: sprinting, sneaking, Minecraft's jump, gravity and fall damage. F5 for third person, F3 for the debug screen
Hearts, hunger and armor instead of health and stamina
Press B for your Minecraft hand and hotbar, E for your inventory with crafting
Build and mine: place blocks, mine the Old World for coal, iron and diamonds, use crafting tables and furnaces
Weapons and armor: swords, axes, bows, leather to netherite armor, with Minecraft's attack cooldown and crits
Fight Content Warning's monsters like Minecraft mobs: they have health, flash red, get knocked back and drop loot when they die
Mobs: zombies, skeletons, creepers and spiders in the Old World; pigs, cows and chickens on the surface
Survival or Creative (flying, every item)
Co-op for up to 4 players, or solo
Join through the game: the host presses Host Game and picks a save slot, then invites friends from the Steam overlay (Shift+Tab, right-click a friend, Invite to Game); friends with the mashup accept the invite.
Needs Content Warning and Minecraft: Java Edition 1.20.2 or newer (1.21.1 recommended), started at least once.