Haha, really? Fantastic! [/Ecclestone]
I believe Rayman would very well need to rely on Lums to exist in the world; they are basically the magical energies that make up all reality for Rayman's world such as our world consists of atoms. Allow me to elaborate using texts from the Knowledge of the World:
Yellow Lums are the 1000 fragments of the Heart of the World; they make up the planetary core, the source of all magic power in the world. Without it, the fairies and nymphs and Teensies alike are practically powerless. They are vital to the survival of many species, I do believe.
First, you must know that the universe is made of energy. Everything that moves around you, everything that lives and thinks is given life by the tiny magical lights which we call... Lums; this is basically what I meant with the atoms analogy.
The Red Lums are full of vital energy; they are a creature's lifeforce, its blood, its heartbeat. It is why Rayman regains Energy when he collects one - it infuses him with more lifeforce, lost lifeforce. Pirates love them, perhaps, because they can fuel themselves off of them. Pure Energy that makes their gears run quicker or whatnot.
Blue Lums contain the first breath. They are the origin of all life. Each creature receives at birth his Blue Lums and keeps them until the day they die; Blue Lums are the breath of the world and its creatures. All creatures require them. Once a creature dies, his Blue Lums are restored to the world to flow back into the pool of Energy that makes up Rayman's Universe. Ray needs to collect them underwater, perhaps, because he's not really supposed to be able to swim. Remember he drowns instantly in Rayman 1 - perhaps he rapidly loses his Blue Lums to the surrounding waters as he remains underwater, which is why we see a blue Energy bar deplete (yes I'm interpreting a HUD element as though it were a story element) when he swims. He needs to restock on Blue Lum Energy in order to not convert into Energy himself (aka dying).
Also interesting is the following passage:
They are soulless monsters, good at only one thing: stealing our dreams that they will never share; to me, this puts things in another perspective: not only should we interpret this figuratively, with the Pirates stealing away all hope from lifeforms across the planet, but also literally - Polokus dreams reality, but he himself is, like everything, made of Lums - the collections of raw Energy that are the superforces of their Universe. His dreams come from Lums. Are they, themselves,.... dreams? Perchance it is so! The Pirates steal away the living people's dreams, their Lums, and lock them up, never to share them with anyone else ever again. This also makes Razorbeard's eating of the Yellow Lum at the beginning of The Bayou more symbolic: with one simple gesture, he eats away at the planet's core - its very source of power -, but he also eats away at hope, and devours the magic folk's dreams. Awesome! Well... I mean, crap!
So to bring my point across most clearly: everything in the Universe depends on Lums. Everything. Not only Polokus, not only physical existence itself (Purple Lums), not only life and breath and knowledge - but, yes, also Rayman. And perhaps, also the Pirates, in some way, shape or form.
PS
Back on the note of Polokus dreaming and nightmares and such, read these three passages:
Unfortunately, Polokus couldn't control all of his creations. His nightmares and negative thoughts gave birth to their own peculiar beasts. So, be careful not to meet up with them. And avoid any nightmares you might meet in your journeys.
After having created all the creatures who live in this world, a harder task remained: creating time. So, Polokus went to the place where all the gods of all the worlds meet, and together they set about dreaming up the future.
To be warned of any problems that might occur, Polokus sent Magic Masks to the four corners of the world. Before leaving, he explained to the fairies that reuniting all 4 Masks would be all it would take to bring him back.
They detail not only what I assumed correct (perhaps the KotW is where my original thoughts on the matter came from), but answer a question we had about the other gods and how they went about making time: Polokus leaves the world to go join the other gods in his dreams. Are they too figments of his imagination? Need he be in full lucid dream-mode to be able to communicate with them?