EAT CELLS OR DIE TRYING! - Mitos.is page
Mitos.is is an MMO where players represent a cell in a petri dish. The goal is to gain as much mass as possible by swallowing smaller cells without being swallowed by bigger ones.

The basic objective is to add mass to your cell by swallowing both food and smaller player cells without being swallowed yourself. Small cells can move fast but will slow down as mass is gained. Cells can be split into 2 or more smaller cells to gain speed but this will increase the risk of being eaten. Mass can also be expelled to decrease your size. Mass is also slowly lost over time.

Experience is awarded based on the amount eaten. Food garners little experience, while eating opponents will garner more. The larger the opponent, the more exp gained. Once enough exp is gained, you will gain a level. Levels allow access to better equipment and items.
As of 16 January, 2016, Tuesdays and Fridays provide double the normal experience.

Your cell is controlled by moving the mouse. The cell will move in the direction the mouse is moved. This can be seen via a small cursor near your cell.
Holding the (SHIFT) key will slow your movement down significantly. Tapping (CTRL) will stop your movement.

Cells can be split by double-clicking the mouse button or hitting the (SPACE) bar. Splitting will fling the divided cells forward in the direction of the cursor. Split cells merge back into one cell after a small amount of time.
Splitting is useful for moving more quickly around the field, or to escape from a difficult situation. It can also be useful as a ranged attack to swallow smaller, faster cells.

Small portions of your cells' mass can be ejected by holding down the mouse button or hitting/holding the (W) key. The longer it is held down, the more pieces are thrown.
This can be used to grow other cells to make them slower and easier to catch, to aid teammates about to be eaten or who are trying to eat someone, or even to bait others into swallowing range. Mass can also be fed to viruses, which after enough will cause them to split.

Items, either equipped ones or ones assigned by the selected game mode, are used by hitting the (F) key. Once used, there is a 1 minute cooldown before it can be used again.

There are 3 main consumables regularly on the field.

• Cells are controlled by every player. Opponent cells that are smaller than yours (by about 10%) can be swallowed. They can be swallowed directly or by splitting in their direction.
  
• Food are randomly scattered around the field and replenish themselves after a short time. When swallowed, they slightly increase a cell's mass.
  
• Viruses will split cells into many cells of varying sizes. Cells will only be affected if they are bigger than the virus, otherwise they will pass right through. Cells smaller than the virus can even hide behind them for protection against larger cells.
  There are 2 types of viruses:
  
  • The plain white virus will simply split and fling divided cells a short distance.
    
  • The white virus with red bubbles will split and fling divided cells AND portions of your mass, making you smaller all around.
  Players can also feed mass to a virus to launch a second one in the opposite direction the mass is fired from (though there are times it seems to go where it wants). This can be useful as an attack against a much larger opponent. It usually takes 3 pieces of mass to launch, though I have observed them taking much more.

Coins also randomaly appear on the field and can be collected by moving over them.

Diamonds will appear on the field of the mode selected as "Today's Special". There is an achievement that awards 600 coins for collecting 500 diamonds. After the achievement is awarded, it will reset and can be done over again.

Free For All
Your goal: Eat or be eatten. Cell mass is scored and a top ten list will be in the top right corner.
As of 16 January 2016, players will be divided into separate servers based on their level.
Levels 0 - 19 in one server. Levels 19 - 69 in the other.
AFAIK, the game never ends unless everyone leaves the room.
It's every cell for themselves!...though players sometimes team up against the others.

Hunger Games (PLAYERS: 20)
Free For All with a twist.
Items and pets will be disabled. Equipment is disabled buring the first phase. One-time-use items will appear randomly in various spots in the middle of the field. You can one have one item at a time, and cannot pick up another until the one you have has been used. After a time, the game will enter a second phase where cells will be revealed on the map and equipment will become enabled. Cell mass is scored and a top ten list will be in the top right corner. Game ends with the last cell standing, or when the time limit is reached.
If eaten, you will NOT be able to rejoin the room.
May the viruses be ever in your favor.

Deathmatch
Dev's answer to the "illegal" teaming in Free For All.
Chat is disabled. Custom skins are disabled and displayed names are changed to random organisms. Equipment and items are all available, but are NOT displayed on the cells in game.
Cell mass is scored and a top ten list will be in the top right corner.
AFAIK, the game never ends unless everyone leaves the room.
Good fight, good night.

Random Team (MAX PLAYERS: 24)
Players are randomly divided into 3 teams when they first join the room: Red, Blue or Yellow. Cell sizes are scored and a score tally will be in the top right corner. Names appearing over the team scores are the largest of each team and the name with a crown is the current leading team. The first team to 5000 points wins the game.
If eaten, you will rejoin with the same team.
FEED ME!!

Soccer Mode (PLAYERS: 6; MAX: 8)
Players are randomly divided into 2 teams when they first join the room: Red or Blue. Equipment is allowed, items and pets are disabled, except for a specific mode item. A score tally will be in the top right corner and players score by getting the ball into the opposing teams goal. The names that appear next to the scores are the player that currently has the ball.
The soccer ball will appear in the center line of the field at the beginning. When a ball is scored, it will appear again after X seconds near the center line in the territory of the team that was scored on either at the far top or bottom. The first team to score 5 goals wins the game. Each player is given a small speed boost item with a 5 use limit in this mode.
If eaten, you will rejoin with the same team.
When in your possession, you can "kick" the ball with the SPLIT move (double-click or (SPACE)). You can pass the ball to a teammate with the mass eject (hold or (W)).
GOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOAL!!!!!

Capture The Flag
Players are randomly divided into 2 teams when they first join the room: Red or Blue. The Red flag will be at the top of the field, the blue flag at the bottom. A score tally will be in the top right corner. Players score by "eating" the opposing teams' flag and returning it to their own. Teams can return their flag by eating the opponent carrier or by ejecting mass into them, causing them to exceed the size limit for carrying(20% bigger than flag?). After a capture, the flags wil be reset after X seconds.
If eaten, you will rejoin with the same team.
You will be unable to grab the flag if you are smaller than the flag cell. You also cannot grab the flag if you are too big. Also, if you are carrying the flag and gain too much mass, either by eating food or opponents, you will drop the flag and it will return to it's base.
Kill everybody. Get the flag back.

Territory War (PLAYERS: 12)
Players are randomly divided into 2 teams when they first join the room: Red or Blue. There are 5 resources on the field. The top 2 are Silver and Gold, the bottom 2 are Lumber and Crystal, and in the center is Coal. The number of territories captured and a resource tally will be in the top right corner. The first team to reach 2000/2000 wins the game.
Players capture the resources by moving into the territories around them and remaining until the area changes to that teams color signifying it's capture. The more teammates in a territory, the faster it will be captured. Capture can also be sped up by ejecting mass into the resource cell. Capture will be stalled if there are opposing team members in the same territory. When a team has captured a territory, resources will slowly begin to be collected. The more territories a team has, the faster resources are collected.
If eaten, you will rejoin with the same team.
When in a territory, you will see a meter at the bottom of the screen showing the ownership level of that area.
He who controls the resource controls the universe

Human Vs Zombies
Players are randomly divided into 2 teams when they first join the room: Zombies(Red) or Humans(Blue). Items are disabled except for specific mode items. Cell sizes are scored and a score tally will be in the top right corner. Names appearing over the team scores are the largest of each team. and the name with a crown is the current leading team. The first team to 5000 points wins the game.
Each player will have a meter on their cell showing their affiliation level. Players can switch teams by having that meter shifted to the other side through various actions, depending on the team.
Humans can be turned into zombies by eating zombie players or eating red mass. Humans who are eaten by zombies can also turn into zombies. Humans can have their meter return to normal by eating mass from a teammate.
Zombies can be turned into humans by eating blue mass. Zombies can have their meter return to normal by eating mass from a teammate.
Each team also will have a different item assigned to them. Humans have an antidote which will shift a portion of the player's meter to normal. Zombies have a "Frenzy" item which will increase the player's speed and put up a shield for a short time. Players have a limit of 5 item uses per game.
Don't open, dead inside

ISN'T THIS JUST A COPY/CLONE/RIPOFF OF AGARIO?
Eh, technically speaking, yes. They both have the same gameplay.
However Mitos.is expands on the concept, adding more play modes, an equipment and item system, guilds, and even a chat function.
Skins also don't cost nearly as much, and you can even have a custom one (pending approval).
Has music and sound too.

ISN'T EVERYTHING BEHIND A PAYWALL?
Not anymore.
Coins are used to buy skins and equipment, repair worn out equipment, buy item charges, buy pets, start a guild, have a private room, etc.
Coins can be bought for $0.99US for 200 coins.
HOWEVER, coins randomly appear on the field during play to be collected. Coins are also awarded for achievements. There's even daily quests that reward coins.
So you don't HAVE to pay. It's just to speed things up, like ALL F2Ps.

WHAT IS WITH THIS #@*!&$% LAG!?
Yeeeeeah, it can get pretty bad sometimes. Even worse than Agario. All you can do is switch your server and hope for the best.

Well, I hope this small guide clears up a little of the new player confusion.
It's my first, so please be gentle in the comments. ^_^

Translators welcome to steal. Just please credit.
Traductores bienvenida a robar. Sólo complacer crédito.
Translators bem-vindo para roubar. Apenas agradar crédito.