flOw started out as a free flash game available online in which the player takes control of an aquatic, worm-like creature, which is controlled via the mouse. The basic mechanic of the game is to 'eat' other organisms that inhabit the environment, which causes the player's creature to grow or evolve. The creatures also have special abilities controlled by the left mouse button.
On October 10, 2009, a trophy patch was implemented.
flOw is a game in which uses the sixaxis function of the DualShock 3 controller. You control these cellular lifeforms and eat other cells floating around the screen to make your creature grow. Throughout the game, you will take part in six different campaigns, and use your creature to go through portals to advance through different layers in the campaign. You can go through the campaign with or without eating any other cells, which will make your creature remain the same size and be more vulnerable. Also eating creatures or cells will help your creature grow, but either creatures bigger than you can also eat cells growing off your creature. The basic goal is to get to the end of the campaign with all of the creatures, and eventually getting to the credits screen, thus beating the game of flOw.
Structure (Flash/PC version)
The PC version features two playable creatures, these creatures, the 'snake' and the 'jellyfish' are also the first two playable creatures in the PS3 version (see below).
Structure (PS3 version)
flOw is loosely based around the idea of levels, but the implementation is quite far from the norm. The player can move 'up' or 'down,' in terms of depth, by eating special blue or red organisms respectively. At each level of depth, there are different organisms, some of which can be hostile. Engaging hostile creatures is never explicitly mandatory for progressing to the next level, but survival at the deeper, more difficult levels, is greatly aided by having previously advanced your creature by eating enough organisms to make it evolve.
There are 5 playable creatures in the main version of flOw, and an extra playable creature in the add-on pack.
First Creature - 'Snake'
The first playable creature is snake like in appearance, growing longer as it consume more organisms. Its unique ability is a speed boost. It can increase its length, and can also develop wing-like appendages on its sides by eating certain organisms.
Second Creature - 'Jellyfish'
The second playable creature is round and jellyfish like. Its normal movement is fairly slow, but its special ability, a spinning maneuver that sucks in nearby organisms, allows it to build up momentum. After using its special ability, it is able to briefly move faster.
Third Creature - 'Dolphin'
The third playable creature has a body which loosely resembles the shape of a dolphin, but gains a long tail similar to the snake creature as it develops.
Fourth Creature - 'Stealth Snake'
The fourth playable creature is similar to the firs. However, its special ability is to cloak itself, and to paralyze other organisms.
Fifth Creature - 'Predator Snake'
The fifth playable creature is another snake like one. This one, however, it develops more aggressive looking body parts, and has the special ability to lock on other organisms and to make a sharp dash towards it, making it very easy to attack other creatures.
Sixth Creature - 'Credit Snake'
The sixth playable creature is yet another snake. This is the simplest of the six, as it simply grows longer with each bit of food it eats, and only has a small boost ability. The only time this creature is playable is during the credits of the game, in which the player consumes a piece of food attached to each credit.
Seventh Creature - 'Bubble Boy'
The seventh playable creature was added in expansion pack released for the game. This creature has the appearance of a small blob surrounded by several sections of hard shell each attached to the body of the creature by tendrils. The creature's special ability is to draw this portions of its body inward, creating a shell, granting the player temporary invulnerability.