Holy hell there are easter eggs ?
Is Meat Boy an unlockable character ?
Yeah.
The game is pretty much like a mix of every awesome FPS ever. There's several classes and you can unlock more as you go along.
I've unlocked Meat Boy, who's really fast but has super low health, but respawns quickly.
His weapons include Ninja Saws (Kinda like super powered shurikens), a handheld Laser (Infinite ammo), and a Portable Demon Maw Portal (Five demon maws max, ammo packs add 2 ammo).
My favorite class so far is the Steve, though. When combined with an Engineer (Engineers in this game can make infinite sentries / dispensers, but metal is rarer), he's extremely awesome. He can build awesome forts, and can craft items.
Faith makes a good char too, she's fastest and has best control and jump and movement abilities, she can steal enemy weapons by disarming them, other wise she just has her punches.
Faith is good for capturing shit, whereas Meat Boy is a good speedy ninja - he doesn't have enough hp to run away with intel with everyone attacking him at once.