The legend of hero

I'll introduce myself
I'm a brave and valiant knight
I will save the princess
From a most despicable plight
Nothing will ever stop me
Nothing will hold me at all
For I can do 12-feet jumps
And I don't get hurt when I fall
I'm a mighty warrior
But no matter how hard I trie
Whenever I touch a snake
I feel I am going to die
I'll have to draw my sword
There's no other choice for me
I wanted to run through the back
But I only move in 2d
Die, you spineless creature!
I'll cut off your head
Wait, is that a gold coin?
Did you eat it? You must be mad!
There's something further along
And it's hard not to stare
What do I see? A piece of the floor
Just floating in the air
Could I be losing my sanity?
Or does this truly defy
The laws of gravity?
I'll jump across this chasm
That's right in front of me
But I'm at zero altitude, how could this possibly be?
As I go forth on my quest
I noticed something strange
The snakes are getting stronger
Just because their colours are changed
As if that wasn't enough
Something else comes to sight
Another floating plataform but this one goes left and right
I paid no attention
To the sign that shows the way
I when through the wall and found
A secret passageway
Inside the secret passage
I found this treasure box
But it seems that someone forgot
To change all the locks
This fireball might be useful in my quest
I wonder how it didn't burn the chest
And since it didn't burn me was well,
I'm gonna use it to send my foes to hell
The wall is way to high
I need something to make me soar
Maybe I could try this hidden springboard on the floor
I can se a bridge
That's a change of scenary
When this happens, I always feel
I'm close to the enemy
At last! Victory is mine!
I've finally killed that asshole
But I just found out
That princess is in another castle