Player-like mob that can be summoned through server doors by using server keys, these are neutral and are a key element to getting progress in the mod, they're fairly weak however always spawn in groups.

A mechanical creeper with a turret mounted on its head! These mobs are VERY dangerous, but there’s good news, they only appear in a shooting range, a structure found underground. Once they detect a target, they unleash a rapid barrage of bullets and won’t stop firing until the target is gone. It’s best to avoid this one..

Your main goal at first is to obtain a Server Key, an item which is found in The Laboratory, a structure which you can commonly find underground.

"A Server key next to 2 of Items/missing"

"Laboratory room"

After obtaining a server key, your next goal is to open up a Server Door, which you can find in Unstable Structures, these generate all over the overworld. After opening up one of these doors, you will let out non-players

You can also gather 3 server keys to create a Third-Party server key, which triples the spawnrate of the non-players.

However not in a crafting table, you need a compressing table to compress items.

Compressing is a very big part of the mod, you compress items by smashing them an extremely large amount of times in a short amount of time, causing them to compress and be shrunk down, eventually leaving you with something new. You can also use it to forge things such as the third-party server key.

Why would you unleash these things? To farm Items/missing, of course!  That's the main component for Aberration of an item, a resource used very often in crafting. This is used to craft basically most things this mod has to offer You obtain it by compressing 3 missing items in a compressing table.

The non-players are mobs that behave similarly to players (as of now they only do 5% of the things they will do). They are just like players in appearance, however they lack.. well, textures. They also seem to be "lag" as seen in their

choppy movements. These will be neutral to the player, until you attack them, they have the same range as the player, however some attributes like their attack damage aren't entirely accurate, being higher than a normal player. They also seem to be learning bunny-hopping, but aren't great at it.

These will drop 2 missing items on death. As stated before, aberration of an item is a very big resource, use for most recipes, such as these.

These are default shapes, used for a very big recipe, being the Offsetter.

The offsetter is really useful tool, not weapon. The offsetter is basically a gravity gun, letting you hold mobs telepathically for 4 seconds.

This also works on players, you CAN use this as a weapon, by dropping mobs in pits, or clipping them into blocks, no-clipping won't send you to the backrooms.

The offsetter has 40 uses and a cooldown.

You can also find cassette tapes, which don't do anything, but they're a replacement for music discs, they vary in rarity and some even (will) have special uses! 

These cannot be played in jukeboxes, you need a tape player for this which has a similar recipe to a jukebox.

The missing blocks have their own full blockset, which is fully craftable.

EXCHANGING:

A new feature where you can find discs all over your world (small amount as of now) which you can then sell using the EXCHANGER.
You can either turn them into a different item or sell them, the items which you get are random and can be both bad and good, depends on your luck.