How long have I been playing?!
This is a seamless game with amazing graphics, and the aliasing issues are all to do with the difference in resolution. The music is very calm and relaxing and keeps you wanting more, while not getting in the way of the game or becoming annoying.
The gameplay itself consists of you, a microscopic organism, feeding off of other such creatures to grow and become more powerful. This happens through either eating tiny creatures directly, or defeating other very similar organisms by eating their health orbs. you yourself have these orbs, and can see at any time how much health you have through them. Once you have eaten these orbs, the enemy will break into several tiny creatures which can be eaten to either restore health or make you grow, depending on the type of creature.
Each of the six organisms you can control over the game have different abilites, different looks, and different levels. Some move fast, others lure in enemies, and others yet poison them. This adds enough variety to the game to keep you going strong through it.
The game is extremely self-explanatory, with a very simple yet fleshed out system for moving though levels, changing organisms, and playing locally with friends. There is one screen with a very limited set of basic instructions when the game starts- but thankfully, that is all you will need.
Once you beat the levels (by eating red orbs to get to deeper layers) with one organism you are given the option to play as that organism is the future in their level and are given a new, arguably improved creature to play with in their own level.
As you progress through the game, the background changes from a light blue to a dark and cloudy black with lighting effects, and several in between. There are different backdrops for each creature you play as, so if you find one boring, the next will definitely change things up for you.
The game itself, when you eat all of the creatures, is about 4.5 hours long, without any breaks. I know so for myself, with personal experience. Further enjoyment can be found replaying levels and playing with friends over ad-hoc.
Overall, this is my new favorite PSP game, and I think you should try it out right now. If you have a little patience, flOw is a very immersive and rewarding game, for only 8 dollars.