Pretty good. Here are a few errors I noticed however:

~ "I run over planes" - I think you meant to put 'plains'.

- "I spikes on my fists" - Left out the 'have'.

- "Its the coolest thing out there" - 'It's' rather than "its".

- "Its really beautiful" - Again 'It's'.

Other then that, it was well written, and the rhymes were real good. I think poems are much better when they rhyme. And don't worry about the mistakes, everyone makes them. I know I have myself. I don't want you to take this the wrong way, because this isn't a flame or whatever. Again, the poem was really good.

~Luv4Knux
P.S- I like how you repeated that one stanza throughout the poem. That one stanza says everything about Knuckles!